Whenever I play with elite AI, so basically every game from now on. I put every AI country at Right of Way, and a couple of days later upgrade it to shared map and shared intel if possible. This greatly improves your relations with the AI.
Trading on the stock market seems a good way for me to keep them relativly happy, sometimes I get a trading embargo, but not really any war declarations, which is basically. Couple of small buy/sell offers a day seems to do the trick for me