Without mini-game you will need 600 energy to get to 600 amity.
While grinding my teeth in frustration I managed to get that much with a bit less than 200 energy.

I always had to build up as much Maximum Favor from start (if it begins with Free Talk or low Accumulated Favor) so that I would have a chance at success on later rounds. For example when I'm asked to get 49 Maximum Favor. Which is impossible to do off the bat.

You could have spent 100 energy to get 320 more than waste 300 energy waving.

Got to 600 amity with a combination of the one mentioned above ^ and this one:

1. Oliviero
2. Lorenzo
3. Vanacil
4. Publio
5. Delmo