You can run and recover from about 3 workouts a week. Any more than that and you aren't fully recovered. This applies to 99% of runners.
It seems like you may be asking whether or not a weekly tempo run is worth it. I believe that it is, with some caveats. A tempo run is different for different people. I use tempos primarily as lactate threshold workouts. You're 10 mile tempo was too long. That'll just leave you drained. Look back at your log, I bet you didn't do much/ran like garbage the days following that 10 mile tempo. Tempos should be 3-5 miles and they're aerobic runs, not lung busters. The point of a tempo run is to push up your lactate threshold, 3-5 miles is all you need to stimulate that adaptation.
When running your easy days, you have two objectives - the first is to recover for the next workout. The second is to get in a modest increase in aerobic fitness. If you want to do more, Wednesday would be a good day to do it in my schedule above, you have an extra day of recovery. There is no point in running easy/recovery runs any faster than you need to. The worst possible thing you can do on a recovery run is to not recover. Its as bad as bombing a workout, maybe worse.
here's how I schedule my week, we are pretty similar runners:
S. long run (workout)
M. easy run (recovery, pace doesn't matter)
T. intervals (workout)
W. easy run (recovery, pace doesn't matter)
Th. easy run (recovery, pace doesn't matter)
F. tempo (workout)
S. easy (recovery, pace doesn't matter)
If you are doubling, add in more easy runs. If you are taking a day off, take off on an easy day.
A couple of other things to keep in mind as you figure out what works for you.
1. You want to run fast, not hard. Sounds silly, but there's a difference. Hard is an effort, fast is a speed. see summer of malmo threads
2. Each workout has a specific purpose. You don't get any bonus points for overdoing it. This is especially true for easy runs.
3. You don't get faster in workouts, you get faster in recovery.
4. Cumulative training is more important than any individual workout. This is why recovery is important. You need to keep coming back week after week to get faster. No one workout will make your season, but it can break it. There's only a handful of workouts each year where you will go to the well. If you dig too deep too often, you end up in a cycle of not recovering, this is when injury/overtraining happens.
You'll get it figured out though, everyone does it a little differently. You learn every year and hopefully change accordingly.