Seriously as this is a very tiring question. TBH, as a player who played when tls dz first started and left for a long time who has come back recently, I don't see how reducing the number of people in alliance is going to help. So you reduce it to 20 guys per alliance. FIne, the big raider alliances which I am also in breaks up. big deal, they form sister alliances and choose not to attack each other. You end up with the same problem.
People WF because they do not want to deal with the pvp side of things. People WF also because they do not have the equipment to do raids. If you cannot raid properly, why bother wasting ammo and meds to raid? Just let them be. Targets is a problem, just live with it. FYI, 3 rounds in alliance wars after coming back, first round was a bit rusty and not so raid ready equipment I still scored 100 pts. 2nd round 300pts, my 3rd round currently and I will be hitting 300. So for those that complain of lack of targets, you're just greedy. You want +10 pts +20 pts kind of targets which is obviously very limited. FYI, since i don't have beastly equipment like noob girl of A0A or Road Warrior of L1N just to name a few obviously there are a couple more guys on the list in my target range, I just try and rack up the points by collecting managable 6/7/8/9 pointers.
If con wants to increase the participation for raiding or pvp, the first thing is you have to allow lower lvl guys to be able to pick up raid quality gear or they players need to think how to maximised resources. I know of big scorers in the top 5 raiding alliances getting by with blue guns and they are not lvl10ish accounts. Island seems to be a good idea but its only for lvl 50s.
The quickest way to fix target issue during war, remove the alliance ranking system and allow everyone to hit everyone who can be hit regardless of the rank of the alliance. If you do this, the points system need to be fixed to pts given based on lvls rather than alliance ranks.
Allowing successful defence to give points is a gd idea. If you get points for attacking, why not defending?
Removing points for trashing? really con? In the good old days, when u get raid, getting trashed is part of the package and since majority of the players have dmu, whats the problem? U can get the resources needed for repairs in what 3-4 auto missions? which is like 20 mins. People who get their base trashed should stop whining. That's why I left the game years ago just before alliance war was implemented cos too many whiny babies whining about me trashing their base when I raid. The saying goes, if you cannot stand the heat, get out of the ******* kitchen.
If you really really want a quick fix to the problem, lower the silly protection times. a full 10 survivor kill gives 12 hours and since most raids will end up like that, you take a target out of circulation for 1/2 a day. Yes I know there are empty compounds or people like JGR who likes to ninja the flags but most raiders will end up killing all defenders and 12 hours of protection time seem excessive.
There are plenty of ways to increase raid participation but lowering the number of people in an alliance? That's just a quick fix solution. It does not solve the problem con. You just change the way the problem is being presented.