Stuff like forced collectivization and rapid industrialization were gaining traction among the party leadership before Lenin bit it, so it probably happens anyways. It probably isn't as stupidly brutal as it was under Stalin, though... we're talking "just" hundreds of thousands dead instead of millions, with correspondingly less damage to Soviet agriculture. Similar story with purges: political purges are liable to still happen, but they won't be the all-consuming things they were under Stalin.
I don't think the NEP being terminated is a given - people like Bukharin and others were clearly in favor of it. It depends a lot on how the power struggles shape up and who is seen as 'winning', since a lot of people usually like to switch over to who they consider is the winning team