Interesting thread, my 1999 4 seater 4/4 is fairly similar in all conditions but noticeably quicker when unloaded, ie no ball chain and two petit packets on board, (mind you more like strapping great lads these days) also the handling is a bit sharper, on the whole I agree less bounce fully laden but roads round here are rather bouncy. Certainly the springs are compressed as the load increases and that should induce a better ride I doubt that major works on this suspension will improve things much, I used to be a bike rider and very fast, it was at serious 3 figure speeds that the bouncy rear end made its unwelcome presence and the mog will not make these speeds, on the bike Fornales gas shocks improved matters. I'll have a crawl underneath though and see how original it all is.
In terms of gear selection I note that this may be a lack of servo which is there on the Ford version, a hard setting and a joy of driving induces an almost clutchless style so when certain conditions occur the gear change may be difficult, try a mental check and see if pushing the clutch harder helps? - just interested