sorry if this post was dead but I never got a chance to get my 2 cents in
ive lulled over this concept a lot in my head over the last few days and how I see it is that 400 skill points is perfectly reasonable
why
it forces people to specialise and trade - it does not mean you have to go off and join a large group you are still perfectly fine doing things either solo or in a small group, yes it means you may need to make an alt or two but what you can do is specialise in one craft and master it then trade your high end resources for other resources you cannot get yourself.
Getting more skills as a purchase poses one problem that no one has mentioned yet - it doesn't just affect crafting but combat aswell and getting more skills means you could become versed in every combat style which as someone pointed out if you can craft everything and fight every style then why play an mmo to begin with?
personally id like it if they separated crafting and combat skill points all together so that you could become a crafter with no combat skills or a combatant that doesn't have any crafting skills. thus giving you a reason to still have alts one crafter and one fighter.
now the point I made above means that you would obviously be able to put points in more than one skill like which is all well and good for crafting as you would then be able to master 2 professions but for the fighting line it does unbalance things a little
so more thought would need to be put into all this if any changes were to happen and besides tbh id really love them to accually put more skills into the game like ultima online had so that it adds even more diversity to the game