[Crex]

Longer hose is a plus for sure.
May run into issues with the 0-10 reg. all will depend on the rest of your torch dimensions: size/length of pipe and size of jet/orfice. there is a ratio to maintain for optimum performance of torch. So many approaches and designs available that it is difficult to figure first time around. Pick a torch design known to work and build to spec as any and every deviation makes some difference +/-.

? - Is your little brass valve a needle valve or just an open/close valve? If just o/c (1/4 - 1/2 turn) then position just past reg. is good as you need to be able to shut things off fast in emergencies without being close to flame/forge. If a needle valve, recommend putting in line close to torch so that you can easily regulate fuel feed and fine tune operation while watching what is going on. Keep in mind that fuel volume and line pressure are related but different animals. Get control of both and you can fine tune your forge's temp to a much greater degree and get the best fuel economy.

A flare at the end of your torch can make a difference with venturi style torches, but will mainly depend on the rest of the forge design as to whether it's needed or not. You will have to try it without to see.

1/32 & 1/16 sound a little large for a venturi torch, but then you are working with a design mod I am not familiar with. All of my forges work fine with .025" to .028" jet/orfice. Have no problem getting welding heats with them. I find the smaller jet is more fuel efficient over time.