Yes, we do have an indoor track here, but the corners are very tight, and I'm usually dealing with an injury before I get a chance to use it. Recently, I've been able to do the odd session with the kids I coach in Feb-early March.
As for the treadmill, I bought one used from a friend (a 2:16 marathoner who decided he preferred to use the YMCA instead of sweating it out in his basement). It's a Pacemaster Gold Elite-- repped for being great value for money. So far, I really like it. I'd held off getting one before this year because I couldn't afford to get one that went faster than 12mph, which is what I still needed for my tempo runs until last year. Thanks to being 45, 12mph with a 1.5% grade is now bang-on.
On the topic of parents and kids sports, I'll just say that "my experience" is one of parents competing with one another using their kids as implements. In my view, even the most well-meaning parents are far too emotionally invested in their kids athletic endeavors, and I think kids can feel this. After structuring our kids sporting activities to the nth degree since pre-school, we need to give sports back to them a little bit and start letting them discover whether they like to do them for reasons other than parental approval. My dad was an extreme case in the opposite direction, having seen me run maybe three times in my life; but, I actually didn't mind. He was still interested in hearing how I did, and I knew from the beginning that running was my thing and my thing alone, and liked it that way. I simply don't think our kids need us to watch them as much as we think, and perhaps hope, they do. Although, I'll admit that, in the case of a very busy single parent, an appearance at a sporting event can be a very touching and encouraging thing for a kid.