I'm a beginner rider too (so not a ton of advice to offer) but I wanted you to know that I bought the SAME bike a month or so ago and paid $899, so $750 sounds like a great deal. I love the bike and knew it the moment I sat on it (although I have since switched the seat after riding a few times on it). I also went and tested out others and found others I loved too, but for the price (my other fave was a specialized WSD) the Trek seemed like the best deal. I definitely do not think it is too much to start with and wished I could have spent more! From the sound of your plans, you will really get good use from this bike - and maybe even in a year or two be ready for an upgrade!

Welcome from a fellow newbie and congrats on finding a new healthy passion! My mother in law is 55 and I am trying to get her to start but she thinks she is too old.... I KNOW she is not and I tell her all the time about the ladies here that are kicking bike butt in their 50's!

Take care!