I am located in Italy and I found a great deal of Tx-Rx Sennheiser 2000 bodypack, but it is set at 50 MW maximum, anyone knows if is it possible to set at 100 (maximum in menu advanced section), usually this is done at Sennheiser under specific request when buying new.

No I don't know how it is done on the 2000 series. If using it in Europe most countries limit you to 50 milliwatts max unless you are in the 826 - 832 MHz band. Also some countries expect you to purchase temporary licenses to use them. A lot of usage info for Europe can be found below from APWPT (Association of Professional Wireless Production Technologies. ) This is up to date as of June 2018 and covers most of the world.

https://www.apwpt.org/downloads/handoutfrequencies2018.pdf

https://www.apwpt.org/

Because of the complexities of what you can and can't use in Europe and the UK re frequencies I ended up not using my dual diversity wireless units over there. The main reason being I encountered interference in some places even on their "specified" frequencies. Especially in Berlin and London. Ended up using of all things for shortish distances like interviews the Rode RODElink wireless kits. To put it bluntly these things blew us away for the price and performance. Never had one drop out, needed no licenses and they ran for what seemed like forever on a couple of AA batteries. Mated with good Sony and Sennheiser mics they worked a charm and gave us very clean audio. A little large in size is the only thing I have against them.

Chris Young
Sydney