Fastwes is trying to tell you something. He offered to save your neck by letting you try one of his XR220's, which, btw, is a fine bike for new england woods. I suggest you LISTEN to him, and take him up on his offer.
Cars & bikes are night and day. Even street bikes and dirt bikes are night and day. 2-stroke MX bikes like KX/CR/YZ/RM are too much for a first bike. Even Jeremy McGrath and Ricky Carmichael didn't start out on a CR250, just as Michael Schumacher didn't start out in an F1 Ferrari, so be honest with your self-assessment. Just because you have respect for power on the conscious level, doesn't mean that you will be able to handle it when it hits unexpectedly (and it will) because your right wrist lacks the necessary muscle memory gained only thru experience. Get something more forgiving, and you will be much happier and healthier. When your skill level outgrows your bike (not likely to happen soon) then you can buy a new bike. A mid-90's era XR200/220 can be bought for around $1500, and if you maintain it well, you won't lose any money when you sell it in a couple of years. But chances are, you'll want to hold on to it anyway, because you will discover that one bike can't excel at everything, so you might decide to add a balls-out MXer (CR250 for example) to your trail-friendly XR220.
BTW, I have a friend who was a club-level jr. enduro champion in his younger days. He returned to enduro racing not long ago. He has the skill to handle any bike, but his weapon of choice is a WR250F, and he competes quite well with it - well ahead of most guys on 2-stroke KTMs. He says a high-strung 250 2-stroke simply wears him out too quickly in new england woods.
As far as wheel bearings go - those are consumable items on a dirt bike, typical replacement period is every 2 years. Fortunately, they are cheap for modern japanese bikes at about $20 per axle. Look at rockymountainmc.com and ronayers.com to get an idea of what different parts cost. Since you're handy with tools, you'll have no trouble doing most of the work yourself. Oh yeah, the front brake rotor is supposed to "float", and calipers have some natural movement too.