I love this deck idea and for advice, I would suggest putting in more creatures to protect Ajani and some spells that search for key components like
Ageless Entity,
Felidar Sovereign, and of course,
Ajani, Mentor of Heroes. If you aren't going to play playlets of these and need to get them on the battlefield, add some cheap "search for..." cards to get the combos going. Overall I think the deck needs a bit more consistency (something I am sometimes guilty of not having) to be successful and achieve your combo of life gain and +1/+1 counters. Once again I love this deck idea as well as colors and I wish the best of luck for you and this deck.