They are some skirmish maps with hostile Gaia camps spawning units 20 meters near your starting base. They are quite annoying, and you should avoid these maps.

CS archers are indeed pretty bad. Archer civs are having a really bad time before they get access to better ranged units. Champion archers are good, but expensive. To use archers effectively, you need to create and maintain distance with the enemy. This can be taxing on APM and ultimately useless, as infantry archers are slow.

https://mod.io/g/0ad/m/delenda-est#description The above mod is for when you get bored of the vanilla game, and want to try something different. Otherwise, to know which mod is good, you need to play the base game first for a while and figure out what you like, or don't like about it.

Shameless self-promotion:  

I feel like archers are close to being good. A few minor buffs here and there. We can look at a24 for ways to make them OP again lol.