Yes you can, and a lot further I'm belgian myself and I've done it. If you don't want to buy reservations it'll probably take 2 traveldays to get to (northern) Italy. 

Yeah with the Global Pass no problem :) 

Reservation free routes Brussels - ICE - Frankfurt - Basel - Chiasso or Domodossola and from here by regionaltrain to Milan can be done on a long railtravelday :) 

Option B via Frankfurt- Munich - Innsbruck- Regionaltrains to Brenner and Bolzano on the Eurocitys Munich - Innsbruck- Verona/Venezia/Bologna/Rimini applies a surcharge of 10€ in 2nd Class or 15€ in 1st class :)

so depending where you come from (rural - city) and where you want to go to (north - south) it could be just 1 travelday maybe ;)

It seems quite possible in one day but I just discovered there is a strike in Germany next week… and it costs so much through France :(

I never ever interrailed through France haha, It just seems impossible and expensive. I don’ even find the regional trains in France for some reason haha. Anyway, the strike in Germany is on Monday and Tuesday (if I’m not mistaken) so any other day should work :D

I’m taking a Thalys to Dusseldorf on monday and that’s no problem but that’s no Deutsche Bahnen..

@SVdV  The problem is that not only the Traindrivers are on strike even some Trafficontroller were on strike luckily most of them are in the other union so there were only few Routes arround Frankfurt and in Bavaria affected by the strike :)

There is still a low risk that the Route of Thalys Aachen - Cologne will be affected from the strike :/

Oh thanks for letting me know, I asked Thalys and they said no problems so but if I arrive late in Düsseldorf I know why now. As long as I get there it's okay tho .

@SVdV  yeah than till yet there was no traffic controler on strike along their route but as said there is a low risk Even if there is a strike some trains are operating on bahn.de they try to keep the timetable uptodate and show which trains are running or not.