To start off, I love 90% of the changes that I've seen, I think the new feat organization is great, the new barbarian is great, the new fighter is great, and the paladin subclasses are great, but speaking of paladin. Please for the love of Bahamut, make Divine Smite NOT a spell and also don't force paladin players to have a mount. 

Not every player wants a mount or a pet, even if it's a classic knight trope, having find steed was an option before, and using that spell is a HUGE flavor decision that shouldn't be a forced class ability. Even if someone doesn't use it, I wouldn't even want the ability on my character sheet.
And secondly, Divine Smite being a spell doesn't sit right. It being counter spelled or halted by anti-magic cones I don't care about, but taking a CORE aspect of the class and just making it another spell is lazy and stupid. Now it's not an innate power paladins have, now it's just a spell they have prepared. That feels awful, please change that. By all means, keep it once a turn and keep it a bonus action, but make it not a spell.

Thank you for reading and I hope you take this into consideration.