Hi
If all else fails fit one of these.
http://www.toolstation.com/shop/Plumbing/Flexible+Connectors/Flexi+Hose+300mm+12+x+12+10mm+Bore/d20/sd2807/p24989
HTH
Hi
To cover the pipes-
Fit the work surface. Tile walls to the pipes. Make a box section from worktop to bottom of boiler with enough clearance to remove. Tile box section with grout lines as wallgrout lines. Mastic to wall tiles.
Hi
You would seem to have blockage from where the basin tap t 's off the hot.
It 's hard to think of much that could get through the OSO and in to the hot pipe to do this, so maybe another tap as lost the washer fixing nut and it as found it way there . Long shot!!!
Cinked or flatened pipe...
Hi
If you want spares for toilets or the like web sites like these are really helpful.
http://www.shop.lunns.net/flush-valves-nproducts14curpage-2-14-c.asp
HTH