Since you have an Ikon pass, I'd suggest Copper. If you go up the mountain, all the greens are lookers right, or skiers left when you look at the mountain as a whole. It's unlikely you'll encounter terrain that's going to terrify you. Although it's not part of Ikon, Loveland is another excellent choice. If you confine yourself to one side of the mountain, the beginner/intermediate area, you will pay about 1/2 of what a normal lift ticket is. The beginner area, in my opinion, is quite vast. Remind yourself that you are trying to learn basics and fundamentals. I suggest fundamentals based on your last sentence, something about, "the skis won't bite." You're probably in the back seat. IMHO you don't need a PSIA level 3 to teach you fundamentals. If you can get an enthusiastic level 1 that will encourage you when you do things right, and perhaps hammer you when you're doing things wrong, that's all you really need. To any trained eye, what you're doing will be immediately apparent. The goal is to have fun and skill build. Expert skiers are not born, otherwise there would be many more of them. You mentioned you have 3 seasons under your belt. If you're still feeling uncomfortable, I'd suggest you need to ADD new movement and balance patterns to your skiing. What I mean by that statement is, whatever you've been doing, isn't working for you. It is totally awesome that you're exploring an alternative solution to what you've been doing, an you realize it. With that said, I'm just making generalizations. If you're really serious, consider a multi week training course. There are some excellent ones in Canada. Nonstop and Core are a couple that come to mind, among several others. Core operates in Whistler/Blackcomb, while Nonstop operates primarily in Fernie and Banff. In both courses, you will also get video analysis, so you can see what you're doing. I'm surprised there aren't more "improvement camps" in the States. There are "Steep and Deep" camps at Winter Park/MJ and Jackson Hole and plenty of other places, not to mention Bob Barne's "Bob's Mogul Camp," which are all excellent programs, but if you're not ready for it, they can be quite intimidating. That's not to say that the instructors aren't excellent and you won't learn anything or improve your skiing. If you go to a "Steep and Deep" camp, understand that that's the type of terrain you're going to ski. They will break you down into groups of similar ability levels.
Yeah...Boots are a big deal. If you're slopping around inside your boots, you're not going to be able to accurately transmit your movements to your skis. If your ski bases don't track across the snow evenly, you will be on one set of edges or the other due to being bull legged or knock kneed. This is a canting issue. Not all people encounter these issues, but if you happen to be one of them, you'll have a pretty bad day on the mountain, even if your fore/aft and lateral balance are excellent. Furthermore, if you don't know how to properly put your boots on and how to buckle them, this can have an effect on your skiing. I've rambled enough. Best wishes to you. Embrace your passion and never give up. Cheers.