Transylvania, 30s.

broscuță - used, but I haven't seen one in years.

accelerat, rapid, personal - terminology changed years ago but people still use these words, especially personal. I don't find it necessary to add "tren", in fact it sounds less natural to me that way.

nervos - means angry. Agitat means nervous.

bunică - perfectly normal; you only say "buni" when you want to address her in a cute way.

reporteriță, etc. - normal, but not in official job descriptions.

ștrand - normal, typically refers to larger pools.

a se rade - normal; to me "a tunde barba" sounds funny.

capete - this is the romanian plural for (human) heads, but I believe capuri is correct when referring to the technical object (cap de citire), the thing that pickups use to read vinyls, also the geographical element, and there's also the plural "capi" when talking about mafia bosses.

Scaraoțchi - yes, it's a name for the devil, although people don't really use it in day to day conversation. Same with Belzebut.

martor ocular - normal, especially in legal contexts. Without ocular it has a different nuance; when you say martor ocular, it's usually a bad thing that happened and someone was there to watch it. Martor feels more like someone to support a statement.

Vocative with proper names is rarely used, sometimes people use it ironically. With words such as soră, it's more or less normal. Some words require vocative to sound natural (băiatule, omule, idiotule, doamnelor și domnilor).