I personally don't understand what the problem could be with regard to the aforementioned problems of adjectives or adverbs (either those compounds exist in common language or they don't, but this is not dependent on adjectives or adverbs; as long as they keep their original meaning they can be quite understandible but still odd as not in use. Changes of course if the compound changed the original meaning of the compound's parts, e.g. honey moon, luna di miele and Flitterwochen),
what I find difficult for a non-German speaking to construct is the genitive thing and singular or plural.
Besides that Donaudampfschiffahrtsgesellschaftskapitän (captain of DDSG) did exist and nothing strange at all about that noun,
Donaudampfschiffahrtselektrizitätenhauptbetriebswe rkbauunterbeamtengesellschaft sounds artificial in my ears,
and "Elektrizität en betriebswerk" quite southern. In high German I would prefer "Elektrizität s betrieb s werk".
I know that "Obligationenrecht" (plural of the determinant part of the compound) is grammatically OK, sounds not high German, however (which would be "Obligation s recht" (determinant singular) again.
Not sure about "Schweinsbraten"/"Rindsbraten" on the one hand or "Schweinebraten"/"Rinderbraten" on the other.
Anyway, similar problems exist also in Italian, e.g., and probably also in French. "richiedenti l'asilo" (and not "d'asilo"), "conflit d'intérêts", "rivista per la TV, "sgabello da piano" "tavolo in legno" and many many others.
Even proper nouns reflect that: Mostly it is "Königstein" (i.e. Stein+König), not "König s stein" which would be more modern, however (alongside "König s berg", "Friedrich s hafen" ...).