1 to 1.5 inch is fine.
When we had a individual ribsteak on the menu at my restaurant, i found that 22 once was the minimum to go for a ribsteak bone in. Otherwise it's just too thin.
As for well done... waste of a piece of meat... but you already know that
What's the reason? Cultural? Scared of red? All the people that used to eat well done and now eat medium rare went gradually... start by trying medium well, after medium etc...

Chances of getting sick eating a rare steak are really low. Usually when there is a bacteria that can make you sick on a piece of meat, it's on the surface, not inside. So even if it's cooked rare, the high heat will kill bacteria on the surface.
That's why there is more danger when eating tenderized (supermarket don't always label piece of meat that are tenderized!), tartar or ground meat. Because the surface of the meat is pushed (tenderized) or simply mixed inside. Usually if i want to eat a rare burger i will grind it myself so i can see that the meat i'm using is clean.
If you do that (burger or tartar), if you really want to play it safe, you can even get your whole piece of beef and boil it for a few second, it will kill bacteria on the surface. Then chill it and then cube/grind it.

I've always preferred pan seared steaks vs grilled.
I also cook with an old cast iron skillet so the crust it gives is unrivaled.

When you do them right med-rare is hands down the best.
I've found the best way for doing steaks on a grill is do a high side/low side.
Sear the steaks about 2-3 mins per side on the hot and then about 3-5 per side on the low.
Always make sure it rests 3+ mins after cooking.

Pan steaks aren't even in the same league tho....

Nothing compares to the smoke flavor but I like the crust.
Hot sear then finish in the oven.

taste the meat, not the heat