I mainly play this game solo and am continually frustrated with the followers system so thought I would float a couple ideas with you;
IDEA 1) Follower health: Just make it so that they cannot be killed. This will open up some options for follower uniques because they are absolutely useless unless you have the 'Your follower cannot die' item.
IDEA 2) I would make it so that they are able to go and pick up progress globes, gold and other crap that I don't want to go out my way to collect.
They are perfectly able to boost to godlike movespeeds to keep up with Crusader horse and other movement skills.. let them boost off to collect the crap and then come back to my side with minimal fuss. I would like to also specify the TYPES of items they go and gather for me.
Eg: Pick up all white, yellow, blue and orange materials and rare 1 handed swords.
It is OK that they do no damage at all really but I would like to have some extra utility added to them.
Making them work liek the cosmetic pets for items is a no-no imho. Basically they would become a bot that loots stuff for you so you can run faster - imho it's a bad idea because speedfarming trades speed for loots and i think it's a good choice to have.
For the rest, it's quite spot on. Atm there are these main issues:
- a non-immortal follower is a useless follower. Once you reach high levels (but even T10 to some degree) the follower will just charge/die continuosly not providing any actual benefit to our character and making it not worth to have. Add to this that the follower is more needed the more you climb GR levels and that it dies even faster, you get the idea.
- tied to point above, all follower relics are useless if it's not the one providing immortality. This sucks because there's a lot of interesting synergies and potential ideas that would just get scrapped/ignored.
- the paladin problem: paladin is the only one bringing heals to the table (and kinda effective ones) thus is the most chosen if not the only one worth to have in high GR. Enchantress has some uses, while Scoundrel seems to me left in the dust.
As you said, giving immortality baseline (or better baseline on legendary relics adding another effect) and giving to each one an healing skill would make them much balanced and viable.
Immortality should be baseline, everything else is pointless.
And I also like the idea that they collect things (for example death breath), but how would that work? How do they give them to you? A system like this only works with abstract numbers (like gold) where there are no items connected.
I am also wondering why there is no unique item that allows you to have for example all three followers up, or even have your follower(s) when in a group (only giving their benefits to you).