Also, I don't really understand how Alliances work.
Some additional info on Alliances other then what is mentioned above:
1) Alliances mean that your relations with a race stays PUT so you don't have to worry about that race going to war with you which in most games is a worry to me even if they're at friendly.
2) If YOU declare war on a race then your ally/allies will not join the war in your favour automatically(for special reasons or on their on prerogative maybe). If an AI attacks YOU only then will your allies/ally be obliged to help you. The AI takes into account your allies as well as you when declaring war so an alliance is extra security.
Imagine declaring war on the Iconians and having 8 other races jump to their defence.
3) Alliances mean that you MUST help if an allied AI is attacked. If you refuse and that AI survives or wins the war. It'll be awful hard to get them to like you again.
Anyway, one thing Ive noticed is that in every single game Ive had (with one or two exceptions), the Thalan and/or the Yor always dominate the map. Especially the Thalan with their influence. Is there any way to try and stop this happening every single game (aside from not including them of course)?
What gives the Yor and Thalan their edge is their high productivity and economics. Not to mention their speed. I'd suggest playing as the Thalan or Yor and finding out for yourself how to beat yourself.
Btw, Thalan influence is due to their range bonuses which gives them the ability to establish themselves where you can't even go yet.
Hope I helped.