If the regulator is functioning and you have no suspicion of a problem, dont worry about regulator... Some function 20-30 years with out need of attention....
Hoses can be a problem, if you are not using grade "T" hose, yes propane can break down hose materials and cause a problem. The problem is more likely to be a leak in hose or chunks of hose materials clogging up torch ports and valves than making soot in glass....
Most soot in clear is from working glass in wrong area of flame....
You can lead a person to knowledge, but you can't make them think.
San Francisco - A Few Toys Short of a Happy Meal