Stoked for you, welcome to the Cruiser fam, fam. I am new to Land Cruisers myself, purchased my first truck a year ago as of 3/16/18.
I can only impart advice based on my personal experiences thus far. I have learned a lot by reading the FSM, getting my hands dirty, and most importantly - asking a lot of questions on MUD. Wealth of knowledge to be had from this forum. I would suggest the desmog be at the top of your list, unless you are in a location where emission regulations require that you have all the smog equipment.
This is for a couple of reasons. A lot of the hoses and components left on from a half-assed desmog will create numerous vac leaks. I am literally in the throws of this process right now. The vac leaks were abundant. The upside is that once the work is done, you will have ample space under the hood to see things more clearly. Secondly, you will become real familiar with 2F, real quick. The process has been laid out very well in the "my desmog thread" and folks are adding input from their experiences often. I watched your video, and from what I can tell, a lot of the issues could be solved with the desmog process. No more spaghetti of hoses. You will be able to work around your carb better, and this may help get your idle problem fixed with most if not all, vac leaks plugged up.
My suggestion would be to visit the TLC Performance website, and get the Desmog Plug Kit, the aux Pulley to replace the smog pump, EGR Block off plate for the J-Pipe, and the Screw on plug for the end of EGR piece that connects to intake manifold for starters.
If any of your smog components are still usable, I recommend selling to someone out West who may need the parts due to emissions regulations. Then use that money to buy more new parts for your truck.
The hose that you grab at 2:36 of your video is the PCV (positive crankcase ventilation). As I understand, it recirculates the warm air from your crankcase back into the intake manifold, to aid in faster warm up. Routing this correctly may assist you from having to hold down the accelerator until the truck is warm, or at least be a move in the right direction. It connects to the EGR (exhaust gas re-circulation) system, which also works in a similar fashion, recirculating warm air back into the intake manifold. It's basically a large vac leak in its current form...
I have photoshopped some images from my truck when I was working on it - hopefully this will help. I am totally an amateur mechanic, so please someone correct me if I am wrong.