20-day Central & Western Europe itinerary. Does this pacing make sense?

Hi everyone!

I’m planning a Europe trip (20 days) and would really appreciate a route check from people who’ve done something similar.

I’m trying to balance seeing enough, checking off enough countries, without rushing too much ( I am okay with fast paced travelling though) . I’m mostly travelling by train, moving west to east.

Current plan (20 days total):

Belgium – 3 days Base in Brussels + day trip to Luxembourg

Netherlands – 3 days Amsterdam

Germany – 3 days Berlin

Czechia – 3 days Prague

Austria – 3 days Vienna (3 days) + Salzburg (1 day)

Slovakia – 1 day Bratislava

Hungary – 3 days Budapest

A few things I’m wondering:

Would you cut/add a day anywhere?

Any route or sequencing improvements you’d suggest?

Are all these places safe to travel alone?

I’m more into walking cities, food, history, atmosphere and off beat experiences than ticking off museums back-to-back. Not trying to do everything, just want it to feel enjoyable and not exhausting.