Yep. The 150 has a luff wire so that part is good. That's a good point about how much line the reel can hold. I'll be sure to ask Ronstan before I commit.
As for stepping the mast, I'm thinking I can either just leave the standard jib halyard on and use it, tying it off once the mast is stayed by the furling setup. Or, I have also practiced stepping the mast using a cam lock cargo strap hooked to an eye strap on the mast, and the bow cleat, to hold the mast up until hooking up the forestay. Both ways work equally well.
As for tension, I have been thinking about that too. If I have enough room, I could make an adjuster to go at the stem fitting. I was a machinist for many years and have a milling machine and lathe in my shop I could make something with. I have also thought about doing as shown in the picture below. I would remove the stem fitting and drill a hole through the deck/hull lip and install an eye bolt for adjusting the tension, of course making everything as waterproof as possible.