Treknology as such should allow for effortless planetary landing of any starship. Their sublight engines obviously create thrust in excess of one gee; their structures can absorb this stress easily. The ships don't sag under their own weight, then, and should be able to hover over a planetary surface, or land on it in any arbitrary orientation (say, balancing on the tip of a nacelle), without the crew or the cargo being inconvenienced since they enjoy artificial gravity anyway.
Perhaps the limiting factor is atmospheric maneuvering, which posed problems for Voyager
in certain situations, too. Impulse engines might work poorly within atmospheres, as suggested by DS9 "The Siege" where diving into the atmosphere supposedly negates the advantage of the impulse-capable interceptors over Kira's sub-impulse raider. Or perhaps the operation of a starship within an atmosphere causes too much havoc in the form of sonic booms, gentler but still massive displacement of air or whatnot. Say, perhaps some system aboard the ship (impulse engines?) creates forces outside the ship that are not harmful in the vacuum of space, but tend to cause major and disturbing air movement when the ship is dipped in an atmosphere.
It's difficult to see a connection between Voyager
's atmospheric difficulties and her flapping nacelles, though. But I think it should raise a few eyebrows that the only two largish starship types seen to be capable of landing, Intrepid
and Klingon BoP, both have strange, moving wings...