Dick said:
if you are on an IFR flight plan and you haven’t got a clearance, keep climbing when in VMC. That’s the only safe and sensible thing to do
An ATC clearance is required for a VFR climb/descent when flying IFR - and be advised for any pilot who may think this is a good idea - ATC WILL no longer separate you from other IFR aircraft, you get traffic info (as per AIP/ERSA). IFR pick-up you dont need the clearance, but equally dont expect separation from any possibly conflicting traffic, just info.
I must stress here, think about the penalties to the other aircraft involved. They may be IFR and plan on getting full separation from other IFRs, if you take VC/VD or IPU, they dont get the separation either.
If talking about a Visual departure, IFR in VMC, it will be to a level below the MSA/LSALT (as per AIP)
Its neither safe nor sensible. If you havent received a clearance its normally because there's a very good reason - 99/100 its a conflicting aircraft.
As for flying into a mountain, the pilot should remain within the area where the LSALT or where Route LS allows him not to fly into a mountain at the level.
Whats the point of having any class of airspace except G & A then. If you arent going to abide by a clearance, or lack thereof, then why on earth did you bother with E?
You say its safer in IMC, how. You may be flying in a cloud but 5 miles further on it may be clear as abell and you come out of IMC and see a beautiful VFR silver bird plowing straight at you at the same level.
There is no safety net in just climbing if you are VMC. There have been multiple airmisses and worst around the world in VMC where neither pilot saw each other. It was only on TV last night about an AeroMexico and a bonanza-ry thing.