A pass will probably save you at least half of what indiv advance fares would cost you-even also counting the extra to pay for all those pesky RES.  Even more so if you still are junior=lower pass cost. As seems usual for newbees and OZzies, they all like to choose exactly those areas where these are hardest to get.

It seems a bit strange combination of places to me, but you will have your reasons.

What fares are likely to be: the homework to check it you really have to do yourself. And thats daft easy by simply using a date of over 4-6 weeks on local planners and see what it will cost (for july youre way too early anyway).

Assuming you will not walk from L to Edi I count 6 passdays-either you take 5 and pay the cheapest ride OR take the 7 day and make some extra trip-or have some leeway for mishaps (always a good idea).

HInt: the very few direct train P->Zü cost an awful lot extra for RES-cut that by using TGV only IN FR and then change to regional trains for onward-often enough.

For Como->IT/Firenze: can so same by taking only local treni till Milano.

Do not sweat or worry about fullness of treni in IT; in fact youre waaaaaaaaaaay to early for then and as treni run hourly or more (its not the Ghan 1/month) you can with a tiny bit if flexibilty also lve till there and pass by a counter. The ONLY train you DO need to RES asap is that €* Lo-Pa. OR use a bus for that to cut cost.

Thank you so much!