So if it doesn't play well, you can edit and adjust it between games until it does
At higher Brackets, deck strength also depends on efficiency and commander choice
Now the only way an opponent could evade infect damage would be to always have a chunk blocker ready, exile Plague Myr, or enchant it with a Pacifism-type aura to prevent it from attacking and blocking
If you do cast the card, it's put into its owner's graveyard as normal once it resolves
Your life total is very much a resource, but without the proper tools to support Cecil, it might be too much a liability
Conversely, you can play a slightly lower land count if you have access to non-lands with cycling