If that's the case, then the warrior sounds like it'll fit the bill perfectly for you. I'm not sure how big of a guy you are, but i'm somewhere around 5'11" and 200lbs and it was a nice comforable machine to cruise with all day. I found that some taller handlebars and lowering the footpegs also helped with comfort. I had the IMS footpegs on mine, they sit a little lower than the stock ones and have twice the surface area so they're a big improvement in comfort, I actually still have them laying in the garage for sale if anyone wants to make an offer.
If you do feel like you need more power later on, you can always kick up the power. Pistons, cams, exhaust, or even go with a big bore or stroker. I think the HotRods stroker kit would be a great way to go especially with an older machine. That kit replaces the entire crank with a new one, so you don't need to have any worries about the stock crank or rod giving out from age and the increase in power output. Relatively cheap too, for the power you gain. Beware of making it faster though, because then you'll want to upgrade the suspension so you can keep that extra power on all 4 wheels most of the time, then better brakes so you're not bashing into trees, then you have it under control then 1 of 2 things happen. Either you make it shinier or you make it faster. I repeated this cycle several times before I realized that although I had a very fast, shiny machine to warrior standards, I had invested so much that I could have walked into the yamaha dealer and bought a brand new raptor 700 with cash.
I know what you mean about the yfz. The fast machines will feel totally out of control at first to an inexperienced rider. Even with all the mods I had on my warrior, and all the experience I have riding (i was competitive with 400's, 450's, and 660's in hare scrambles and did pretty good on the mx track), my raptor 700 still felt like an out of control beast for the first couple days. Sometimes it still scares the **** out of me and makes me wonder why the hell i bought something so crazy fast and still proceeded to make it even faster. I could only imagine what a 450 would feel like to a novice rider. Now the big power is just the norm for me, and riding an average machine like a 300 or 350 makes me feel like i'm riding a lawnmower.