Such a leaning spring exerts more pressure on the piston against one side of the casing than against the other, and tends to wear the casing out of round. Some players use the second or third joints of their fingers. This method pushes the piston against the opposite side of the casing, causing the piston to misalign slightly and produces bad valve action. Over time, this constant pushing against the opposite side will wear the valve casing out of round, creating valve leakage. It is almost certain, that a player who plays this way will have valve action trouble in the future.
Screws have a tendency to loosen and back themselves out over a period of time.
A little time spent checking over your instrument now, will save you a trip to the repair shop later. It is the practice of some players to try to stop valve spring noise by applying Vaseline to the spring. This is not advised, the Vaseline is liable to get into the valves and when it does it will gum and cause trouble with the valve action. To remove noise, try new springs or switching springs from one casing to another. Also try increasing tension by stretching the springs slightly.