Milan, Bologna, Innsbruck, Salzburg and Vienna - 10 days trip in July 2018

Taking a train from Milan via Venice to Innsbruck would involve doubling back - unless you want to stay in Venice.

You can look up train times on the DB website: https://www.bahn.com/en/view/index.shtml
Enter: From: Milano, to: Innsbruck Hbf and a date and time.
It will show you all the possibilities. The quickest connection (just under 6 hours) is via Verona. You can also go via Zürich which will take about 2 hours more.
You can also look up your other trips on the same site (Innsbruck - Salzburg - Vienna)

Milan and Bologna - 2 days
Innsbruck - 1-2 days (Swarovski Kristallwelten)
Salzburg - 2 days
Vienna - 2 days (flying home from Vienna)

I think you are rushing around too much. It is better to count nights, not days, and never have less than 2 nights in any location.

Swarovski Kristallwelten is some distance from Innsbruck. According to the website there is a shuttle bus from Innsbruck. It is mostly a sales opportunity.

Hightlight for the trips include Hallstatt, Gruner See (the Blue Lake) and Salzburg Festival.

Will you have time for all of these? Hallstatt and Grüner See also require transport to get there, and will take most of a day.
Grüner See = GREEN lake

I would suggest skipping Milan and Bologna and heading out to Innsbruck as it is an all day trip. Add the time saved to Vienna, as it is a great city worthy of more time.
For the time allotted and your itinerary, you would have done better to have flown into Munich.
See RometoRio.com for travel options from Milan.

Two days for Milano and Bologna are very short. At least you should go by the Frecciarossa high-speed train between the cities to save travel time.

Thanks for your recommendation! Will take into consideration for my travel plan.