USB - USART communication problems

New interpreter error: MEMORY

I'd focus on this as it's the first one. It means you've run out of memory - presumably your code has some kind of memory leak or just keeps putting data into an array.

I'd use process.memory().usage to see how much memory is used - you may see it going down over time. Best bet is to see if you can figure out which function calls cause the memory usage to go down and you can work from there.

You can also use E.getSizeOf to recursively show how much memory is used by various different things. If you haven't already I'd update to the latest cutting edge build of Espruino as there were some changes made a month or two ago that make E.getSizeOf return more useful information

it's posible to enable software or hardawre flow control on the USART1?

Yes - Serial1.setup - http://www.espruino.com/Reference#l_Serial_setup

Is it posible to disble the BLE console?

Yes, you can just set uart:false in NRF.setServices