Tucked away in the south-east corner of the board are the dark islands of the Dutch East Indies. Although there are only three home centres, the number of centres within reach are many. The Dutch are similar to Turkey on the standard board, easy to defend against single power attacks but slow starting compared to the other powers. Although the Dutch have three guaranteed neutrals to pick up - Cey, Sar aud New - the risk of going for all three is leaving the Java Sea open to a British fleet in the first turn. The risk of this happening is probably not worth getting three neutrals as you could lose a home centre all too easily.
The Dutch are probably the biggest sea power on the board as building armies is never really an option until you have established a few mainland coastal centres on which to convoy. It is possible to win without ever building an army as there are 24 coastal centres that are just as easy to capture as some of the closer inland centres.
So how do you see the opposition powers
British: The British are going to be a major pain in the backside to you, they are the one power that will severely restrict your advance on the mainland and will block your way westwards to protect India. An alliance with the British is possible, of course, but this requires you to consider an option to expand northwards through the Philippines and to face Japan. If the British are true to their word, then the likelihood is that he will be fighting Turkey in the west but helping you fight the French in the east. If you really trust him, you can leave Java Sea open, but you would want to be heading north as fast as you can, so open to JS, TS and Sar, then move TS to take New and JS to CS, build fleets in Bor and Java and continue the push. You may consider only taking one build from Sar and move TS to CS and JS to SUN.S as you will want to beat Japan to the Philippines. You need to make sure Japan is not getting his own way in the north against Russia and/or China otherwise you will meet his mass of fleets head on and start getting bogged down in a no-win situation. If the British have been successful beware of the stab, as he will be unlikley to be able to do anything against Japan directly.
Frankly the British must be a target at some stage, so make him an early target, Singapore is a British supply centre in the Java Sea, so you want to take it as soon as possible, from there Malaya and possibly Bangkok are on the cards, Better to make Britain an offer for Singapore if you are considering an alliance with him, it is a vital centre that you need for your own security.
China: Being so far from China doesn't mean to say that you won't have things to say to him. China is a useful ally against the British, Japan or the French, he is a land power who needs a friendly sea power, and you are of little threat initially. An odd Chinese fleet should do you no harm, and indeed is best encouraged for use against Japan. His fleet or fleets can aid your expansion in the eastern seas while he is occupied with matters inland. The scope for co-operation is almost endless, you will not be fighting over the same centres until the French are out or the British are doing badly. Any contentions will arise in the Bengal/Upper Burma/Rangoon areas, so resolve these in your early Diplomacy so that you don't fight for them later on.
French: Both yourselves and the French are two small powers that have great potential and the likelihood is that the larger powers want to erase that potential as soon as they can. With this in mind an alliance with the French can be mutually beneficial, but competition for the same supply centres will be a problem. Your first target has to be the British; you can both combine attacks on the Malayan peninsular area to prevent his growth in that area, but you must also consider what is happening with Japan. If Japan is expanding fast you may need to diert some units against the Philippines. The French have more naval influence than yourself in this area so his help should be forthcoming, you will both fear Japan, so mutual understanding is vital. In the west you should be the main benefactor with India falling under your own control. Try and keep French fleet builds down to a reasonable(?) level, he has a lot of opportunity to use armies in China and beyond; too many fleets will make him consider a stab on you, whereas you want to get the stab in first, the French centres are needed for victory, so the alliance will only be possible until the mid-game. Leave it any longer and it will be you who suffers the wrath of the French.
Japan: Your other island neighbour in the north can be a superb ally or your ultimate downfall. You are both in the main, sea powers, and you will undoubtedly meet halfway between your respective homelands, but with careful planning you could have the strongest alliance on the board. Once you have swept up the islands in the Pacific between you, you can then pile west 'juggernaut' style. Japan into Russia and China while you hit the French and British, the power of this alliance has yet to be seen in a game in the UK, but once it happens it could be compared with the fearful juggernaut of Russia and Turkey on the standard board. In reality the Dutch/Japanese alliance could end in a stalemate war of attrition in the east allowing one of the other powers to steal the lead. If you are sure that Japan will be aggressive go for control of the Pacific, even leave builds behind to get position as you will not get the chance later. The Japanese islands are useful supply centres, and if you get that far you must be in with a chance of winning.
Russia: One power you have little to do woith is Russia. Your relationship with him will be almost purely diplomatic to start with, trying to swing him against Japan or against China, or even Turkey if it suits your needs. A second eastern Russian fleet should be encouraged to contain Japan, and hopefully Russia will be building quickly diverting attention from yourself. This happened in my game at World DipCon?, I was the Dutch, the Russians built 5 on the very first build season and everyone looked north while I quietly picked up centres in and around my corner of the board. One advantage in staying friendly with Russia is that you won't want each others centres for victory.
Turkey: The western side of the board is going to be of less importance than the east, but encouraging Turkey to move against the British will keep the British occupied for a while, you could ally against the British but at the expense of leaving the Pacific open to Japan or the French, there are fewer centres to be gained in a larger area so consider this allience with care. You are more likley to come into contact with Turkey in the mid-game after the British have been defeated and you both have units in and around India, this is where you may have to start fighting the Turks and hopefully your good relations with Russia or China will come to fruition. If Turkey comes south he will have a lot of fleets and is unlikley to switch direction against Russia if he has control of the eastern side of the Indian Ocean, he will be looking for the same centres as you.
Turkey is useful in keeping the British occupied but you don't want him to be too successful, the barometer of success is who gets to India first.