First plambic questions

The following is my plambic plan. I'm looking for comments for improvements in this plan. There's also some questions at the end if you have time. Thanks a lot!

My goal is to ultimately blend this with a younger batch or two to make a gueuze. I would ideally do this in three years but I will likely be moving in two.

Ingredients for my 5 gallon batch:
6.5 lbs Pilsner malt
3.5 lbs unmalted wheat
1 lb rice husks
4 oz, 4-year old Willamette hops aged 4 years
White labs sour blend 4.5 oz

The Brew:
Mash in at 100 degrees using 13.75 quarts (1.25 per lb of grain). Slowly draw off ¾ a gallon, and then boil. Add wort back to the mash. Repeat the process many times over 2-3 hours until the temp is 170. Vorlauf, then sparge over 1.5 hours with 190 degree water until I have 6.5 gallons of wort.
Boil for 1 hour, add all hops at the start of the boil.
Cool to 65 degrees and siphon to 6.5 gallon glass carboy. Do not aerate. Pitch white labs sour blend and dregs of a bottle of Friek by Odells. Ferment in room that averages between 63-68 degrees, wait 1 year, then taste.

Questions
1. Should I consider adding new water during the step mashing process and then boiling down 8ish gallons of wort?
2. What would be an ideal mash time using this step process?
3. Should I use yeast energizer or nutrient?
4. Are the rice husks necessary? Should I take them into the mash water calculations?
5. Should I add any oak chips to inoculate them with bugs? Could I do this later on if so?
6. Should I filter out the hops with a grain bag or leave them in?
7. Is Friek by Odells worth pitching?

I'm not sure how well your mashing method will work. The liquid is where most of the enzymes are (which is why decoctions are usually pulled thick), this may cause problems converting the starches to sugars when you eventually get up to the saccharification range. For a sour beer it isn’t a big deal if you don’t get complete conversion, but you do need some conversion. Is your wheat flaked or completely raw? Rice hulls aren’t a bad idea, you can wait until the end to add them (.25 lbs should be enough).

I had a sample of Friek at SAVOR a few days ago, didn’t get much sourness/funk (but it certainly wouldn’t hurt). I would aerate the wort as well, you want a healthy/quick start to fermentation (my first Lambic took 4 days to start fermenting and had some off-flavors from primary fermentation). For most sour beers I pitch some healthy/known Sacch in addition to blends and dregs. Some yeast nutrient wouldn’t be a bad idea, but probably isn’t necessary.

Usually Lambics are boiled longer to get rid of any funky aromatics from the aged hops, may not be necessary if your hops smell fine.

Oak and Lambic are a classic pairing, but more for the microbial properties and oxygen permeability than anything else. You could certainly add ~.5-1 oz of boiled oak cubes either at the start or well into fermentation.

I would get rid of the hops since the beer will be sitting in primary for so long. That said I’ve visited a brewery that has a dry hop sock stuck in one of their barrels from a few batches ago and they haven’t had a problem.

Hope that helps, good luck!