Ten-day training cycle

As I ease back into running, I'm considering moving to a 10-day training cycle temporarily. I've always used 7 days, and it usually has a few key features:
- a long run, always on Saturday.
- an easy easy run, a slow jog on soft surfaces, on Sunday.
- speed work. At least I USED to do this, Mondays at group track (canceled; everyone joined another Tuesday group but it's a farther track and a bad day for me).
- off day or cross-train day

The other days were just moderate running (although at times I was really consistent about a mid-week ten miler at a not-slow pace). The problem with this cycle was that I only got in one hard workout. I've tried two, but I could never adequately recover, and would end up hurt. So one speed session per week it was, and that meant too many moderate miles. See, speed session lead to recovery sessions. One speed session per week means just one easy day per week, too. And not enough variety running: almost all my runs were the same easy pace.
Another problem I foresee with the weekly schedule is handling cross-training. If I try to cross-train more to avoid injury, I can either sub an easy day for cross training and only run 5 days a week (not enough miles to improve) or sub an off day for cross training and never get a day off (hello, injury).

I've put together a tentative 10-day training cycle, and an example looks like this:

Long (long and slow)
Very easy (short and slow)
Easy(regular old running)
Hard
Cross-train
Easy
Hard
Very easy
Off
Hard


So let's compare months:
Regular 7 day training cycle                 Ten day cycle
Long runs: 4                                             Long runs: 3
Hard days: 4                                             Hard days: 9
Very easy days: 4                                     Very easy days: 6
Off/cross training: 4                                 Off/cross training: 6
Easy/moderate days: 14                           Easy/moderate days: 6

As you can see, this gives me much more variety, and increases very easy or non-running days by a third. It is, however, a hefty jump in hard days, but "hard" isn't necessarily death-by-track every single day. Hard workouts can be mid-week long, tempos, fartleks, hills, or speed work, depending on the plan. I would definitely be redefining "hard".
The obvious drawback to a ten-day cycle is that your long runs could end up on a weekday. That shouldn't be an issue for me now, as I build up mileage, but if I were training for a half or full marathon, I'd have to reconsider.

What do you think? Doable? Safer? More dangerous? Have you ever used a ten-day plan?