Scotland -- Kilt
Ireland -- Beerland
Japan -- Kawaii Land
Sweden -- Ikea
Finland -- Per-ke-le
Russia -- Cy-ka Blyat
Hungary -- Gulash
Serbia -- Kebab remover
Aragon -- Desperta ferro
Brittany -- Camelot
Netherlands -- Smoke Weed Everyday
Qara Qoyunlu -- Kebab 2.0
Wales -- Sheep F*cking
Russia -- Commies
Ming/Qing -- ♥♥♥♥♥♥♥♥♥♥♥
Portugal -- Bacalhau
Commonwealth -- Super Kur-wa
Scandinavia -- Vikings
Spain -- Siesta Conquistadors
Granada -- Iberic Snackbar
Navarra -- Euskal Euskal
Brazil -- Hue Hue Hue
Transylvania -- Dracula
Crimea -- Crymea a river
Turmids -- Kebab 3.0
Livonian order -- Irrelevant clay
Galicia -- Bacalhau's father

Sad thing there's no Iceland :( but Catalonia should be Not Spain, of course :P

Catalonia : F*cking Separatist

Israel=Hypercube
Kazakh=Block
Ukraine=Opressed Russian Minority
Poland=Polan
Germany=Reichtangle or Allemaigne
Austria=Dr Osterriech
New Zealand=Sheep F******
Netherlands=♥♥♥♥♥ or Underwater
United Kingdom=Rosbif
Brazil=Hue
Russia=Rossiya
Lithuania=Litwa
Norway=Oil Bork
Morroco=Al-Morroco
Algeria=Al-Algeria
Najd=True Sunni
Serbia=Kebab Remover
Ireland=Eireland
England=U Wot
Navarra=Insignificant
Inca=Spanish Colony
Iquoris=British Colony
Ulm=POWER
Romania=♥♥♥♥♥♥♥
Bosnia=Slav Kebab
Albania=New Kebab
Estonia or Kurland=Eesti

Also sorry i forgot some

Lousiana='Murican Baguette
Australia=Gday
Champaign=Wine
Mecklenberg=Neo Nazis (Due to the fact that 20% of it's slected parties at the German election were Neo Nazi groups.
Bohemia=Rhapsody
Canada=Eh? or Seal Clubber
Catalonia=INDEPENDENCIA!
Chile=Coast Stealer
Columbia=Cocaine
Corsica=Napoleon
Danzig=Rightful German Clay
Haiti=Voodoo
Sapmi or Sami=Reindeer
Nepal=Rawr
Brunei=Oil Rich

Have any of these names been added?

Ulm - Ulmpire
Venice - Buckets-o'-Ducats
Papal State - POPE HAT

Here's the Polandball Wiki: http://polandball.wikia.com/wiki/Polandball_Wiki

It might be better to use "Polan" or something else for Poland - "Kur.wa" is a very strong swearword in most Slavic languages, including Polish...
Also, "Eesti" for Estonia would sound way funnier than "Irrelevant"
And come on, EU4 ends at 1820, commies didn't even exist back then - what about "These damn Russkies" or "Motherland"?
Lastly, I don't know if there is a limit on country name length, but if there isn't, you should totally change "Krakow" to it's ridiculously long full name "Free, Independent, and Strictly Neutral City of Krakow with its Territory".

Brittany - Haggis Baguette

Ireland - Oirland
Italy - Best ally ever
Norway - Not Sweden
Bohemia - A Song
Ulm - The Mighty Empire of Great Ulm
Serbia - REMOVE KEBAB
Byzantium - Rome??
Switzerland - Neutral
Crimea - Russian or Ukrainian?
Navarra - Always a vassal
Japan- Weaboos
Netherlands - Weeed
Spain - Nobody Expects!
Hungary - Gib Transylvania
Russia - Squat Cy.ka
Canada - Always Friendly
Catalonia - Not Spain
Aragon - Catalonia 2.0
USA - Freedom
Poland - Lithuania Eater
Lithuania - Help

France = Big Blue Blob much better than baguette isn't it