Probably but it depends on your itinerary. Please read the section on this site about reservations. A Global pass is valid on most lines in Italy provided it is operated by Trenitalia or Trenord. All high speed trains in Italy require compulsory reservations at an additional charge. International trains into Italy are also subject to a supplement in most cases. Don’t use the Eurail app to plan. Use DB for Germany and Trenitalia for Italy. You’ll have to decide the places you want to visit. Both Italy and Germany are big countries by European standards

Between DE and IT you have tocross at least also either Swiss or Austria-also included in global pass.

IF you mean this as a very broad general question: best ALT is likely hire-car, but these have draconic high surcharges for dropping of in other countries.

Limitations on the pass are more by company and type of train and not so much stazione.

When planning your holiday consider how many days you will be using a train and how long you are staying in a particular city.
We find travelling on day 1, staying 2 nights, travelling 1, staying 2……. works well. You can realistically travel up to 8 hours in a day after breakfast and checking out so you arrive mid to late afternoon, get checked in and have an evening out. Obviously shorter journeys mean earlier arrival.

For your idea of Germany and Italy in 14 days  (subject to your arrival and departure airport) ,I would propose a routing including  either Amsterdam or Brussels, onto a couple of German cities from Berlin, Cologne, Dresden., Leipzig and onto Munich. From there I would do either Vienna to Venice or Munich to Verona and on to Milan. Then you will need to get back to your arrival airport.

Your choice would be a 5 or 10 travel days Global pass.
 

Given the overall cost of your holiday I would suggest you pay the relatively small premium for first class.