So many good ideas around here. I posted already somewhere on this forum but this seems more the right place for any ideas about pirates...
Normal Pirate raids and bases can be slightly stronger than they were/did in entrenchment, but not much. The raids were merely a nuisance after the opening stages of the game were over and thats ok by me because I agree with Rincewind pirates are after all...just pirates. No match for fully beefed up (teched) Solar Empires' fleets and starbases. The pirate bases were hard enough to kill in entrenchment (took some real effort) but its ok if the effort is made a little harder. Like a player really needs to have a BIG fleet (1500+ supply?) with many many armor and weapon system techs developed.
The missions may be as strong as a player is willing to pay the pirates for. After all, the player bleeds credits for it. It should not be cheap. A good ship you buy for them pirates could be depending on the the best techlevels and ship types taken from all players who have been given missions to the pirates so far. No superships.
Simple mission example: Im a TEC player and I want to pay the pirates for a mission. Before me, an advent and later a vasari player payed the Pirates for a mission. During those private dealings with the pirates (including the current one, being mine), the advent player had the best techs + shiptypes at the moment of the dealing. Thus, the Pirates will equip themselves with the advent shiptypes available to them at the time of their dealings with that race. Let this be Aeria drone hosts and Illuminators (The advent and vasari players may already have teched up to better ships but the pirates dont know how to make those...yet. that is, untill one of those players again gives the pirates a misison). As the pirates can get by metal and crystal on the black market a bit cheaper than we can, they can buy the needed resources to produce a drone host for say 2600 credits, and an Illuminator for say 725 credits (Illuminator bought for 380 credits + 60/100*better_marketprice_metal + 55/100*better_marketprice_crystal). The Pirates then ask the player 3325 credits (2600 + 725) per 2 ships, as it is planning to build those types 1 on 1 base and not telling what ships that might be...they decide that themselves. I think deciding shiptypes and what mixture is something the AI can handle. So if I wish to send around 30 pirate ships to my enemy I must pay them pirates around 50,000 credits.
When the Pirates sortie to the target, their fleet exists (in this case) of 15 drone hosts + 15 Illuminators, having the armor, hullpoints, shields, damage, abilities and antimatter that the advent techdevelopment allowed at the moment of their dealing with the Pirates (not their current techlevel, however that might be the same). On top of those 30 'good' ships the pirates can include their usual raiders (what can be seen in entrenchment nowadays, not diplomacy lol).
Well you can basically do anything with that. Either the pirates build from all races that dealt with them, creating a fleet of TEC, advent and Vasari ships or they just build from the tech and ships of the paying player of this mission(so the target has some clue about WHO send those pirate bastardo's) or they build like explained in the example or...or...
Of course any system should have a maximum, a cap. Because so many ships do not pop up just like that and pirates too, need supply let alone command.