Wow Thread 4 na!

So here I am again, planning a DIY Europe take 3 happening for 3 weeks from mid-June to early July. Summer and peak season but I don't have a lot of choice kasi yun na ang summer break sa school din. I plan to tour Central Europe naman.
Here's my planned itinerary so far:
Day 0 - Depart Manila
Day 1 - Arrive in Budapest, Hungary. Rest. Some walking then dinner.
Day 2 - Budapest: Royal Palace, Buda Castle, Matthias Church, Fisherman's Bastion, Chain Bridge
Day 3 - Budapest: Parliament, thermal baths, etc. etc.
Day 4 - Budapest: everything else, some shopping, late afternoon travel to Vienna, Austria (2h45 by train). Overnight in Vienna.
Day 5 - Vienna: Old Town, U-Bahn to Stephansplatz
Day 6 - Vienna: Schönbrunn Palace
Day 7 - Vienna: Ringstrasse Tram & Walking Tour, everything else. Train travel to Salzburg-3 hours
Day 8 - Salzburg: Mozart's Salzburg
Day 9 - Salzburg: The Sound of Music Salzburg. Train travel to Munich, Germany-2 hours
Day 10- Munich (copy mama squeak's Munich IT in the Germany thread)
Day 11- Munich (copy mama squeak's Munich IT in the Germany thread)
Day 12- Munich (copy mama squeak's Munich IT in the Germany thread)
Day 13- Munich to Interlaken, Switzerland (or Lauterbrunnen?) - 7 hours. Explore Lautebrunnen or Grindewald.
Day 14 - Interlaken to Jungfraujoch. Explore Jungfraujoch.
Day 15 - More exploring. Interlaken to Lucerne - 1 hour. Overnight Lucerne.
Day 16 - Lucerne to

?
Day 17 - Switzerland vs. Germany
Day 18 - Switzerland vs. Germany
Day 19 - Switzerland vs. Germany
Day 20 - Switzerland vs. Germany
Day 21 Depart Europe
Day 22 Home sweet home
I need your thoughts from Day 16-20. I've been reading about Switzerland vs. the Frankfurt area in Germany and andami masyado na options. Decision paralysis nako.

In Germany, I'd like to explore Heidelburg and Frankfurt. In Switzerland, ummm, ewan ko. I've read about Geneva, Bern and Basel but nothing is appealing to me. Thoughts? Anyone who has done both?
Sa ngayon, nasa $2,300 to $2,500 ang budget ko excluding airfare and pasalubong. Included na yung intra-city trains, local transpo, accommodation, tickets, meals and misc. I haven't done cost comparison on passes pa.
@sis vainbutpretty: Pwede! Ginawa ko ang DIY Europe na solo (and very first solo trip ko) and this thread has been so helpful as a support group din. Tiyagaan lang ng planning and preps talaga.