P.S: I said that because around the 80% of the problems in of my last week has this low rating
Bad problem rating

I think this is a false problem.
What matters is not the absolute value of your rating, but the percentual of players above/below that, wich gives you an information about your skills compared to the population of players.
If you alter the system's settings for all players, those who yesterday standed above you, will most likely keep being above you: so if your rating grows due to a different rule, that same rule will work for other players too the same direction...
Then you could possibly reach 2000, but 2000 would not have the same value and meaning it has today.
Remember those who have a stable 2000 rating today, are those who were able to face the same condition you are facing and succeeded where you failed: you won't reach them if you don't get better, no matter the rules as long as they are the same for everyone

There are problems with very low rating and extremely difficult. I don't understand why a problem with less than a 5% of pass has 1400 of rating... My problem is the same as you can have if you play always vs people with 300 points less than you: you win : +5 , you win : + 6 , you win : +3 , you win : +5, you lose : -30 ... I think if we have a rating is for having problems according to it, not +- 500 around...

I just checked: after I solved a problem, its rating adjusted losing 7 points, just the way our own ratings do when we get defeated. Hence, I see no point in complaining about problems' rating, since they are not assigned an arbitrary level but they "earn" their points on the base of their performance at putting in trouble players.
If you are rated higher than the problem and you deserve it, prove it by solving it; if not, it means you are not that higher rated than those who were able to solve it.
Once again, remember ratings don't have an absolute meaning, they're just a useful tool to make a comparison between many people.

When some problems of 1400 points have less than 5% of "pass" I think the rating of the problems has failures.
Btw: You have 3 problems in tactics...so you are talking about something you don't know. I hold a high rating for a long time, but you only need one bad day to go down to hell, where the problems are almost always below your level and not exactly so much easier.
I am an addicted to tactis (more than 9600 problems already done), but I am SO TIRED of having problems which has 300 points less than me, because if I pass I get +8 (or -13, if I do it in the average time, for example), and if I fail I get -30 (even if the problem has 2% of pass).
I had 2049 a month ago and now I can barely hold 1700... can someone change this with -100 +100 or something like that (as we can do with the normal games)?
Thank you