One of the problems I foresee in the strategy is that you won't learn how to ride in a group if you're soloing off the front regularly (or, conversely, sitting at the back or off the side waiting to make a move). This skill is critical at the more advanced categories, even "only" the Cat 3s.
A huge casualty of this "solo off the front" thinking was Rebecca Twigg, in her early career. She was so afraid of the field she'd ride behind by a few lengths or off to the side a few widths away from the group. She lost a couple big races by very small distances (notably the Olympic RR), but she was strong enough to do a 160km 42x18 training ride before a 50km men's points race at the Olympic Training Center (which she won).
Strength-wise if you can win solo in the 5s and 4s you'll be a 2 or a 1 by the end of the summer, if you can handle yourself in a field. A couple Cat 5s did that last year, one going from 5->2 (and getting 4th? in his first P12 race) and another 5->2 (winning a few road races on the way). Both were extremely good pack handlers, able to read a race, etc - in fact that first person beat me regularly as a 3 no matter what I tried.
There's a local Cat 1 who used to solo off the front and win. This was his strategy:
1. Get free of the field, usually early, usually by doing a hard effort, 30-33 mph for a couple minutes.
2. Steady TT at 28 mph.
3. Listen for time gaps from friends/allies/spectators/etc.
4. If gap drops by a few seconds, go 31 mph for a lap.
5. If he wants to increase gap, go 31 mph for a lap.
6. Whatever happens, don't go slower than 28 mph.
7. Continue until you win race. For him that meant, one time, doing 47 or 48 miles solo, in front of a chasing P12 field.
I lose his strategy at #2, sustaining 28 mph minimum for the next 60-90-120 minutes.