If it's surgical grade steel then your piercing will not fuse to the bar. In general the rule (as far as I understand it) is to leave it alone for the first day to allow the wound to clot, then begin your cleaning regime. One thing I would advise is if you are using warm water and salt, use sea salt, not table salt.

It's pretty much up to you whether you turn it, as some say it causes tearing, while others say it allows the wound to breathe. I don't think there is consensus as everybody heals differently, and everybody is susceptible in different ways.

For me, I usually clean it for the first couple of days (without turning) then leave it alone as best as I can. While I can happily say I've never had an infection, I have no idea of this is best practice, but I've never been advised against it by the piercers I have used in past.

With regards to using a gun, given its your lobe I don't have much of an issue with it, as it is probably the safest place to use a gun due to the increased blood flow in comparison to the rest of the ear. In future though I would advise injection (needle), as most professional piercers do not use them. The process is less traumatic, has less chance of infection, and it gives the piercer more control over positioning.

If you are seriously worried, so could go to a professional piercer and ask for advice. They might expect payment or simply refuse you, due to it not being their responsibility for aftercare for a piercing they didn't do, but ultimately they are the most experienced.

And ultimately you can just remove the piercing and allow the wound to close, then go elsewhere to get it redone.