Get some pictures up for me once it arrives!
I think an indoor trainer is definitely the way to go if you're serious about getting fit and keeping fit. They start around £120 but at that price point they're loud and not particularly road-like.
Unfortunately I can't help you with the wife situation...she's your problem
I jumped in at the deep end with clipless pedals and bought a set of speedplay straight away, one tumble onto the tiles in my kitchen the day I got them, 3 on my drive at the end of rides, and an embarrassing one at some roadworks with workmen (not directly caused by the pedals, but the floundering to get up once I was in the mud and nettles was all the pedals!) and I think I've finally got the hang of them (until next time). On the plus side tumbling to the side is basically painless because it happens in an embarrasing slow motion topple that you just can't prevent
Because I'm a light rider and the speedplay have a fairly stiff entry it took me 3 days of clipping in and out, wedged between the foot of the bed and the windowsill, to finally loosen them off and break in the clips enough to feel safe on the road. The MTB SPDs are meant to have a much smaller learning curve, though.
The difference between flat pedals and being clipped in is huge. You feel connected to the bike every time you try and put the power down or the road gets a bit bumpy, and you also get none of the pedal skipping under your foot as the chain bites on a new gear which used to drive me spare having to reposition my foot all the time! I'd never go back now.