Hi Nyman, welcome to Turku ;-)
When are you coming?
I'd say that allmost all central area caches are Ok, except maybe some mysteries.
How many caches have you planned to search?
Send me mail in my private mail: vilhyt@gmail.com so I can give you my phone number and be a help desk if you need help (in the case I'm available during your visit). I've been searching caches abroad and I know how frustraiting it can be not to be able to find caches due to language/cultural differencies.
Here's a list of caches that I would recommend. They are not too difficult and have text also in english.
Joulurauha GCZE7G
Puolalanmäki GC1F5VN
Ravintola Samppalinna GC16TEJ
Betel-kirkko GC137EQ
Apteekkimuseo GC11RXA
Pääkirjasto/Turku city library (Turun ytimessä 3) GCNJ1E
Turun ytimessä 4 GCT7HG
0 km: Turku GCZ1AH
Lönnrothin polku GC143VT
Jokiranta GCHV7Z
This cache is more difficult and it has some climbing. It is not recommended if you have better clothes on/ if it's slippery or wet, but it's very rewarding:
Six feet under ground GCVH35
For the bank question I would say that all banks are quite same, maybe best choice for a tourist would be Forex near the market place in Hansa-shopping centre. Also in swedish: www.forex.fi
Please mail me for more info. These are all, but last one, easy and quick caches close to the centrum.
Some of them I've searched long time ago so they may have changed little bit.
comments from other Turku area cachers?
Viltsu