Is it possible to gain some fgs by playing this game selling items?? and if so how long before it will start being worth it?

Is it fun?

possible but doubtful for new players as they won't know what has value for sale.

yes

ok i might consider installing it...

no and yes.

No,
you not sell items on jsp, you sell them on poe trade vs currency
and you sell currency on jsp

Yes,
currency are items

You can sell anything useful for fg, but it takes time to learn the economy.
Also the game has its own learning curve, depending how deep you dive.

Once you know what you are doing you can make loads of fg.

I make more steam trading then i possibly could in this game no matter what my skill level is.

The value of items plummets sixteen hours into a league after that its just grind grind grind for thousands of exalts. So tedious and boring.

You understand that's how arpg's work yes? It is the epitome of grinding, look at the company's name for petes sake!

PoE is really profitable the first 2-3 days, then the prices drop off quite significantly. But if you know what and when you are doing stuff you could make loads.