Looks like you’re on the right track on sensible upgrades to your bike. Tires and touch points almost shouldn’t be considered “upgrades” as much as just making the bike work for you. On that note, new grips can make a world of difference for a relatively small price.
If, for whatever reason, a tubeless conversion just doesn’t work for you (some lower-end wheels just don’t cooperate) I’ve heard good things about the Tannus Armour tube liners (about $40 each). I don’t personally have any experience though.