like dave said,
hose from heater to reel needs to upgraded, i used house grade plumbing pipe and fittings.
check with insurance too, didnt have a problem with mine, just said get a lpg sticker and will be fine.
flow was easy to get right, 2 minutes to adjust the low pressure screw on gas heater and sorted, they all have these.
vent wise, i just have doors open and that works for me,
not sure how the micro bore goes stiff tho, mine always soft, and stiff when the cold is runnin.
some brushes can curl due to heat, i use gardiners and a vikin when needed a good scrub.
glass can crack in cold temps, but i not have had that happen and i worked down to -9 just got to alter the temp of the water and look at the glass, older glass cant take it that well.
dont see it a waste of gas personally, £13 for 2 weeks work, cheap a chips! plus can get more done in a day so make more per day.