> A recent post advised that the Bayern-Bohmen ticket would be valid until Plzen.
Bayern-Böhmen Ticket (Bavaria-Bohemia Ticket) was always valid till Pilsen/Plzen. The question was only if the "Ex" trains are still covered. This train type was for a while not listed anymore on the first hand resource
Covered are the train types "EX, R, Sp, Os" of the CD (Czech Railways).
> Yet another post advised that the Bayern-Bohmen ticket was only valid for trains beginning with "R" and not the ALX EX train
That's nonsense. Bayern-Böhmen Ticket covers in Bavaria all regional trains. These are the regional trains operated by DB (German Rail): S-Bahn, RB, RE, IRE and all trains operated by other railway companies (ALX, VBG, BOB, BLB and many more).
While inside the Czech Republic (as far the area is covered by a Bayern-Böhmen Ticket) it covers regional trains "Sp, Os" and some long distance trains "EX,R" (R stands here not for regional but something like rapid).
Does however not mean that the train will be any faster after Domazlice when it will be "upgraded" type wise from a regional train (ALX) to an express train (EX).
The schedule as such won't change till December. Re-checking connections shortly before traveling never harms. There could be e.g. events or technical issues which need track works on short notice. Would however normally not influence the departure time. But re-routing or a bus substitution service on a part of the route will mean a later arrival time. The risk that something like this will happen is however very low.
Edited: 4:46 pm, March 23, 2013