You might try removing the valve and cleaning the components first. Make sure you turn off the isolating valve (water supply) to the toilet before you remove anything. Replacement internal mechanisms are not too expensive, your local plumbers merchant will advise you what you need if you take in the...
Have you spoken to Salamander? They deal with these types of problems all day and will be the best people to speak to, you can call them on... 0191 516 2002 (technical) or email them tech@salamanderpumps.co.uk
A good quality, well weighted shower curtain will not be dragged in by the shower draw. The thread count in a shower curtain can be a good sign of quality, a high thread count should stop 'misting' come through the material if you have a power shower. Or, you could install a glass shower screen, or ...
