I think I am exactly the type of person that should have 2C-P. I know what I am doing with psychedelics. I have plenty of experience with level 4-5 shroom trips, and have some experience with LSD. I have also tried salvia on two occasions. I don't see how I could be in for "serious trouble". The worst case scenario is I take 50mg of 2C-P. And that would only be if I literally ate all the 2C-P I have. Even if I did take 50mg of 2C-P that probably wouldn't be too dangerous. Psychedelics are generally very safe. I am aware that you can OD on many phenethylamines, but the therapeutic index is generally very high.
Your concerns are unwarranted. Lets say I was retarded and divide the 50mg it two. I would probably end up with two piles around 20-30 mg each. If I took a dosage of 20-30 mg of 2C-P I would be in for one crazy trip, but I wouldn't be in any serious physical danger. I would probably just have a level 5 trip for like 8 hrs and then It would probably gradually weaken until I would be baseline in 24hrs.
Now lets say I divide the 50mgs into 5 piles. Yes I may end up with a larger pile, but I'm gonna fucking notice the difference between a 25mg pile and a bunch of 5-10 mg piles.
Now to the scale. Why don't I buy a scale? Because I don't have much money, and I don't generally deal with large batches of drugs except for weed and shrooms, which can both be eyeballed.