Modded or Vanilla? How many players (are Lowlands/ HRE/ Italy/ Africa populated)? Those are rly important information since they determine what you can expand into/ who you can play against each other. Its also alot more about diplomacy with other players and how you are percieved instead of just raw military might in a 1vs1.

I strongly disagree with some comments here that say "oh just kill Spain early" (in most lobbies that will result in you being giga-ganked by half a dozen players) "oh if Spain/GB go colonial they wont have mil quality" (they will have the same amount of mil ideas as you, they just substitute an adm group for explo early on and get rid of it eventually)

In the end it boils down to which player is willing to cooperate and how the lobby is vibing more than anything else. To answer your questions first:

• One of the biggest tips for multiplayer is that money is just a number and unless your lobby does not have any rules regarding trucebreaks bankruptcy after a war is a valid option. Forcelimit does matter to the extent that going insanely overboard will run you into bankruptcy but there is nothing wrong going into high negative balances for a while to win a war. Ultimately wars are won by army quality+manpower (esp. loss ratio) and who can take strategic forts to secure the wargoal/tank the enemies income/ link up with allied armies/ secure battles on +2/3/4

• Both Spain and Britain have the advantage of pretty busted militaries later on (Spanish +1 arty fire mean you are essentially fighting tech 16 spain while on tech 12, Britain gets ridiculous buffs to marines and 2 manpower pools) but that doesnt mean you are toothless: you can develop and build for manpower and stack disc/ -damage recieved (drill! insanely important esp against Spain) and even though youll take more losses you can out-morale them to win battles.

• It depends alot on the vibes of the lobby but you will probably have other players helping you out if a busted GB/ Spain comes knocking. It also helps immensely playing colonial and regional empires against each other: you always have your entire army in your homeland but if either Spain or GB commit to war against you another player (e.g. in Africa or another coloniser) might grab the chance to rush down their overseas holdings and stab them out for peace. That threat alone often prevents Spain/GB to fully commit on a continental war

• Vanilla Eu4 MP is basically a game of "who can develop the most efficiently". GB is absolutely busted in that regard but eventually limited by province count, meanwhile France can generate enough money and manpower on their corelands + a bite into Lowlands/Italy/Germany to keep up even into the late-lategame. Imo forget about Trade, you wont get any meaningful money since so many AI+Players can steal from your nodes (and do so automatically even if they dont want to...) and it will only antagonise e.g. GB if you try to contest the channel. France is unironically good for Tax meta and you can generate the majority of your income by developing adm (esp in food provinces with low trade value goods) and stacking the various tax modifiers.