"Basel to Lucerne
We'll just do as the locals do and buy tickets at the station and hop on. OR SHOULD WE PRE BUY TICKETS BUT NOT RESERVATIONS?"

That possible but doesn't make much sense:
Either you buy a web ticket valid for a certain train only (and you will get into problems if you miss it) or you buy a ticket at the railway station counter resp ticket machine (for any train within a certain time frame, usually a full day).

Did I understand you in saying that I should check with Byron for getting all these tickets? I thought he only sold passes.>

Well he does do individual seats too I believe but as he works thru Rail Europe but you may pay a bit more than booking yourself thru the national rail sites - not sure but give him a call and see what he says - IME he'll give you the objective take.

why do you have to have 8 seats together - nice if possible but 4 together for each family would be fine too it seems - that means a block of seats - 2 x 2 seats with a table in between - the other block could optimally be right across the aisle.

but 4 seats together may be easier to book online yourself it seems.

Having the 8 as close as possible would be nice. While they don't have to be immediately beside each other...we just don't want them to be in different cars if we can help it.

I'll give Byron a call.

Yes being in the same car is key - or at least one party of 4 in the same car - worst case scenario all split up - unlikely I think - if taking domestic Swiss trains you may want to go first class as IME you will always find several or many empty seats in the same car - not always so in 2nd class.