My first time connecting in ARN so just want to be sure:

LH business (FRA-ARN) connecting to TG business (ARN-BKK). US passport.
From the ARN website, it seems both LH and TG use terminal 5.
I have 1hour, 25 minutes scheduled as the layover. 12:15PM to 1:40PM

I assume there will be both security screen and immigration process, correct?

How difficult/time consuming is the connection at ARN?
Anything I need to be worried about or aware of?
Any priority lines for Business Class that I should be looking out for?

Thanks.