The basic structure you've outlined is fine. Although I would recommend that you ensure you eat enough in your five hour window, including plenty of fat. You're obviously quite young, so you need to eat enough to fuel your growth.

I can understand your parents reaction. However, if they see you eating big in the five hours, and you don't become unhealthy, you would hope this is enough.

Show them paleohacks!

I am a once daily IFer myself, and have been for quite some time. 19+ hours is a typical day for me.

I hear the 16 hour number from Robb Wolf and Martin Berkhan in terms of optimal muscle growth, but I am not entirely convinced. Liver glycogen can last a couple days. Besides, muscle is active storage tissue, just like fat - breakdown and synthesis are constantly occurring, it can be drawn down and replenished over time without much worry. Muscle protein synthesis seems to correlate with the relative change in plasma amino acid concentration, so breaking your fast will induce large spikes in MPS. Does this outweigh the extra breakdown in muscle? Who knows. From my experience, long periods of once daily eating with occasional two day fasts has not impacted my lean mass in the slightest.

Doing HIIT fasted will greatly increase HGH secretion, if you are looking to burn some serious fat.

Weight training is a slightly different story. There are major questions around when MPS is actually increased in response to resistance training. Some studies show it happening immediately, in others it peaks later. You should check out Lean Gains for weight training with IF, Martin gives an intro protocol for fasted training here. The gist of it is take 10 g BCAAs before fasted training, and don't worry about it.

You can't say that you're 100% something and then say that you're not. Butter may have a lot of fat, but it's not on the paleo menu.

I don't see anything wrong with the way that you're fasting, but you might want to consider eating after the workout.

Why are your parents "freaking out about this"?

I would show them the following, but in particular order;

http://www.youtube.com/watch?v=BVn-jmCi4zI

http://www.youtube.com/watch?v=fh3QfFP_yCM

http://www.youtube.com/watch?v=9y8PMx1gRL4

Ask them to read The Paleo Diet by Dr. Cordain, The Primal Blueprint by Mark Sisson, and/or The Paleo Diet Solution by Robb Wolf for starters.

If I recall correctly, fasts over 16 hours and less than 48 hours can have deleterious effects on the muscles. Ideally, a 14-16 hour fast would provide optimal health benefits, so I would start the feeding window more towards noon.

Also, since IF'ing puts a stress on the body, you should have little to no daily stresses and you should be getting adequate sleep (8+ hours per night). If these issues aren't addressed first to get cortisol levels in check, throwing in the IF will do more harm than good.

What you're describing is "NIF": non-intermittent fasting. As I understand the principle behind IF, it reproduces the occasional and random (non-periodic) lack of food that a paleo hunter-gatherer would experience. What you're doing is not in that spirit, and, without any science behind it, I have no basis for guessing how healthy or unhealthy it might be. It's really self-experimentation, and your parents may be justified in freaking out! How about this instead: get a many-sided die, and every time it comes up '7,' do an IF...

Yes, you are setting your training back by not consuming protein/carbohydrate pre or post workout.

For a better understanding of why, Jeff Volek has a great presentation highlighting some of the better research on the subject.

http://ifile.it/t12grxk/dietary-manipulations-strength-training-volek.ppt