Would like some feedback on 4.5month Balkan/Central Europe in August trip

Hello, I’m 29M and this is my first time solo traveling, first time going to Central Europe and also first time staying at hostels. Here is my itinerary:

Date | Location | Days | Notes
—|—|— | —-
Jul29 | Vancouver
Jul30 | Berlin | 10 | Day trip to Leipzig, Hamburg, maybe Dresden
Aug9 | Prague | 7 | Day trip to Český Krumlov
Aug16 | Krakow | 10 | Day trip to Auschwitz, Warsaw, Katowice
Aug26 | Budapest | 8 | Day trip to Skanzen, Szentendre, Pecs
Sep3 | Zagreb | 3
Sep6 | Plitvice | 3
Sep9 | Split | 3
Sep12 | Hvar | 5
Sep17 | Munich | 7 | Will be in here for Otkberfest but considering daytrip to Stuttgart/Nuremberg if I get bored of it
Sep24 | Vienna | 5
Sep29 | Bratislava | 4
Oct3 | Ljubljana | 5
Oct8 | Florence | 7 | Day trip to Pisa, Siena, Cinque Terre
Oct15 | Rome | 7 | Day trip to Ostia
Oct22 | Naples | 5 | Day trip to Pompeii, Capri
Oct27 | Dubrovnik | 5 | Day trip to Mostar
Nov1 | Sarajevo | 4
Nov5 | Belgrade | 5 | Day trip to Novi Sad
Nov10 | Istanbul | 7
Nov17 | Cappadocia | 3
Nov20 | Cairo | 7 | Aswan and Luxor
Nov27 | Athens | 5
Dec2 | Amsterdam | 7 | Day trip to hague/bruges/ghent, will probably stay a night in brussels
Dec9 | London | 7
Dec16 | Dublin | 7
Dec23 | Vancouver |

Budget

* $20,000 USD

Explanation on itinerary:

* Main goals are seeing roman empire history stuff , some partying and eating unique food.
* I want to take this trip very calmly and not be rushed. I expect to have days where I wake up and just chill for the entire day without doing anything, which is why I might be staying at places longer than usual.
* Going from Budapest -> Croatia -> Munich .
* I want to be in Hvar/Split before the offseason begins but I also want to be in Munich for Oktoberfest
* At the tail end of trip, I want to experience what it’s like to be in an European country that is winning during the World Cup. Right now I have Netherlands and England, but that could change depending on whose winning/losing.
* Right now I’ve booked most of my stays at party hostels as I never experienced them before, but I expect this to change if all the bad things I hear about them here are true. Nowadays I feel catatonic without a full nights sleep.
* I want to make the most of the 90 day Schengen limit, but I also want to be back at home by Christmas .
* Places like Spain/France/Portugal/Greek Islands I plan to do in another trip .

Questions:

1. Anything that looks out of place? Could 5 days for Hvar be too much?
2. Is it worth going to Bari and taking the ferry to Dubrovnik? Or should I just fly there from Naples?
3. How are the world cup parties? Is it worth it just to travel to say Barcelona to enjoy the atmosphere if Spain is in the midst of things?
4. How busy is it during Sep-Nov? Would I need to prebook the popular hostels or would I be able to walk-in and get a bed? I know for August it’s pretty busy, which is why I’ve been prebooking for that month.

Would like some feedback on 4.5month Balkan/Central Europe in August trip