Pre-cum Drops: These drops comes when ever any one is stimulated sexually and it have no effect on the health but blue films are very dangerous for sexual health and can cause erection failure after marriage.
Cold Penis: Penis is the part of your body and if ur body feel cold then ur penis will also feel cold. so there is no issue and u are normal.
Erection: Its seems that you are watching blue films regularly and also thinking about sex excessively that is y u are having so much erection. It is not harmful for health but if it last for long time then its the medical emergancey