yes. very difficult
In which time span can I reach 2000 Elo?


In the best circumstances it takes people a few years.
In normal circumstances people decide it's not worth the effort and stop before 2000.
And they're not wrong... it mostly comes down to the individual and how obsessed they are. If you enjoy playing and learning about chess every day, then one day, 10 years from now, you may be an FM.

with average Iq that's the highest you can reach no matter how much you work may be you start at age of 5 with best training for 20 years that can be achieved by you

It depends on many things - native talent (think Morphy or Capablanca), strength of memory, motivation, willingness to work long and hard - and still there are no guarantees. I remember asking a coach once in school if I trained hard enough, could I run 100 yards in 10 seconds, His quite succinct answer, which I've never forgotten in 60 years, was, "Are you Jesse Owens?". In other words, no matter how long and hard I trained, I didn't have the inherent skill to do so. I would just concentrate on enjoying chess and not let any arbitrary numbers be your goal. You're bound to get better, but to what level it's impossible to predict with any degree of accuracy. But it's not worth worrying about anyway.

Naa, average IQ with structured best case training (starting at age 5, professional trainers, etc) a person could probably be GM.
Or not. Obviously not everyone has the potential to be a GM, mostly my point is IQ doesn't matter, or rather, that 100 is enough.

In which time span can I reach 2000 Elo? Is it difficult?
It took me three years to reach 1800. Read, play, study tutorials, etc. Learn from your mistakes!

Should I continue working w/ my 1600 coach who has helped????
Or perhaps sign up to chess university????
Btw is it also true that chess is 99% tactics...


I played through a couple of your defeats. In the first one a straight queen hang. In the second one I saw a series of positional errors before you dropped your queen on a skewer.

One of my favorite chess quotes is something along the lines of, "The BDG is the fastest way to reach 2000. From either side."

Magnus Carlsen managed to add 1000 Elo in a year to go from roughly 900 to 1900. But, he worked really hard at it, is a genius, had a good coach, and is one of the most naturally skilled players ever. So, I'd say several years at least.

Eventually any chess player will hit a plateau where they will find that advancing their rating further can only be done through detailed studying. There then is a second plateau that players reach, which is one’s absolute best.
Note that the second plateau you mention is almost always self-imposed. That is, the person could continue improving, if they were willing to focus on the correct topics, spend the necessary time to correct their defects, and dedicate themselves to such studies. Usually, there comes a point where the requirements for further improvement exceed the time and effort a person wants to spend on a hobby.
I think this post is serious. But, serious or not, it is exactly correct.
In which time span can I reach 2000 Elo? Is it difficult?