Hey there

I'll just try and answer this in a short paragraph. The thing is, trolls don't really need fixing - they perform very well in the context of Mordor's gameplay. So you're kind of presenting a solution for a problem that doesn't really exist. Trolls are already awesome; they do massive damage against buildings and are faster than infantry, which makes them great at harassing. Combine this with free orcs who swarm the map and protect them from danger and you've got a really nice one-two-punch. When they get their armour, they start to destroy everything and can only really be stopped by a fully upgraded army.
Addressing some of your points: Making them resistant against archers is a huge problem, since they are already decent against pikes - with good micro, you can fight pikes in melee and even win in a 1v1 scenario (don't trample!). Removing their weakness to ranged would mean that they could beat any other type of unit, which would cause huge problems as you might imagine^^
When you don't have an outpost, you can do a few things:
- Level your heroes (you don't need to fight to do that)
- Build six barracks and drown the enemy in orcs
- Get a few armoured trolls with hammers (siege) and rush your opponent's base
Especially the last thing is difficult to defend against, because trolls are quicker than rams and do amazeballs damage against structures. If you catch your enemy off guard, you can even destroy his entire base!
If you have other questions, ask! I hope I didn't discourage you or something, because that certainly isn't my intention. It's great to see you put so much thought into this instead of just complaining and whining, keep it up
