Loads between 75-85% of your 1RM are considered high intensity. Or less technically, if the fifth rep makes your eyeballs pop, that's high intensity.

Multiple sets of high intensity lifting increases insulin sensitivity.

K.I.S.S. Keep it super simple(or keep it simple, stupid!)

Heavy is relative. You should A. Sweat, B. Breathe Heavy, C. Win.

3 days of heavy has left me with adequate time for recovery. I guarantee we are all different, and its going to take self-testing to find your point.

Determining recovery time when coupled with heavy weight is a little easier, because if you havent recovered, youll be weaker. Try to lift just a little bit more each time, if youre failing, you need more rest between heavy days. The heavier weights you get, the more rest you will need. Elite Lifters can need up to a week between peak lifts to recover fully. Beginners can lift every day to every other day with little to no issues.

Because of my schedule, I've made my own workout split. My age and goals see things a bit differently from straight CrossFit. On Mon & Wed, I have scheduled (for 3 months) name WODs, both girls and heroes. Then, depending on my schedule and long run, I do a powerlifting workout on Friday or Saturday. I also work on my weightlifting skills, gymnastics, and kettlebells, usually on Saturday. My powerlifting works on the 3 major lifts, but I also do some neuromuscular training that is more CrossFit related. For instance, I may take 455 pounds and do 2-3 inch partial squats 30 times. I have to make sure I do it on the rack because when my legs finally give out, they don't give any notice at all. My overall weights have gone up, bodyfat is down, and I've lost 12 pounds since Paleo. I also do trail runs on Friday, bike on Saturday, and short-fast run on Sunday. Good luck.

The problem with going to a crossfit affiliate for only some of their programming is that you can't get the full deal. I would talk to your affiliate trainers directly, or perhaps the owner/head trainer to see how they think you can work this.

If the MWF metcons are relatively short you could add squat, deadlift, and a pressing movement for 3x5 pre-WOD. I had been doing that for a while and it feels good but it adds a lot of gym time.

This is simple. If you walk away from your workout feeling like you just survived something similar to a near death experience you have lifted heavy things.

I follow the method developed by Dr. Bernstein: 1 rep of your maximum that you can lift even 2 times; then decrease the weight incrementally for each set, lifting the new, lower weight doing as many reps as you can. When you get to the set where you can do 20 reps, you're done. There is NO resting between sets - just change the weight as fast as you can and do the next set. The idea is to exhaust the muscle on the first set, and then keep working it to complete muscle failure. I've done this for only 3 weeks, and I can't believe how quickly I've become defined and am even starting to build muscle. I do this 2-3 times per week.

anything larger than pink or purple dumbbells? ;-)

I do this program http://stronglifts.com/stronglifts-5x5-beginner-strength-training-program/ Less taxing than crossfit. Fits in perfect with the dictate to "Lift Heavy Things"