Arse in gear.

Hi all.

I need to get  my arse in gear! So, as promised when I was allowed to join the illustrious Cabin, here are some of the, very many questions, I have to annoy/bore/make you laugh with my lack of knowledge.. .

The feed & return are going to be 22mm, can I go straight to the TRV/return, or do I have to reduce them to15mm?

What make do you recommend for TRV;s/thermostat? (Manual thermostat, I'm too much of a Luddite to go high tec! ) 

Most of the rads are1400x450, (Stelrad, 305mm between bottom of rad "hangers"), any thoughts on the best wall brackets for them? (The walls are Victorian brick, lath and plaster, or plaster board). I'll adjust fixings to suit.  Or just the cheapest? I can make them, (free), if need be, but got a bit on my plate at mo.

Is the gas pipe 22mm into the house, as I need to make holes for it?.

"The main room doesn't need TRV's, just a thermostat". I love my open fire, (it heats up the whole house, and I get a lot of free logs from work! ) but, as my mother is coming to live with me soon, and I want it to be warm for her, would it be better to put the thermostat on the upstairs landing to ensure a more constant heat? I don't light the fire until minus temps/ and I have the time, (unless I'm "entertaining") , but that will change/stop...

My apologies for the multiple questions, but I have so many...( from do I need a katsu pump, to which is the best pipe lagging?).... I'll polish the begging bowl for them later.

Karl