Maybe you want to mod in a small to medium happiness bonus (maybe 30%?) to your top tier core buildings? I think the averni can only build up to level 4 so keep that in mind. You can either do it for everyone across the board or just for your own faction.

Its as simple as typing in a single line in the export_descr_buildings file. Shouldn't damage anything if you do it right and if you make a back-up before you edit it you can tinker away to your hearts content without worrying about messing anything up.

That should offset most of your major problems without giving you a major advantage. let me know if you try it and what you think about it.