This is based on my own personal experience with an MMO, I currently play, which has also earned my loyalty for the past five years and hopefully more years to come.
The following is the model I currently enjoy and think is fair:
Buy to play (One must buy the base game and every subsequent major expansion, not including small content updates).
Pay to Play (Subscription based with occasional free trial weekends and refer-a-friend programs).
A balanced/healthy mix of cosmetics split between in-game achievements and a cash-shop with zero(0) pay-to-progress elements.
Absolutely no F2P as it will undoubtedly turn into pay-to-win(P2W) with a toxic community.
I personally would not play any game labeled as F2P. Nothing is free.
Ultimately, your business model will heavily depend on the quality of your work. if the game is beautiful, works as intended, and the game loop is fun, it will sell itself through word of mouth. In my opinion, the best marketing strategy is a loyal playerbase who love the game and not just power through it until something better comes out.
That's my two cents.