hi jagh9
1-I haven't played these games but yes you can build world with a lot of work and time but I think you cannot import a world from a world construction program, the limits will come from the strenght of your machine and the number of object in the camera field(distance)
2-whith a recent computer/graphic card you can handle much more textures and fine models that let's say 10 years ago when db get released but you won't be able to produce a fine high end DX10 game
3-although I've decided not to turn to DBpro until I fully know DBclassic you should be aware that pro's got a much more eficient technic acording to graphic transparencies, also pro can manage to deal with bones animated character(but you will need programs like 3dmax to produce them(easily.?.) as far as I know)
you can buy a lot of extensions for pro that will save you time and experience coding it yourself(but it can turn expensive for an individual and hard to control/manage)
now to conclude I think you can produce a very good game(like max payne I presume) and then easily(at least not impossible)transport it to pro if you need some ehancement but even then you may not reach what big teams can make out of their mind...
(sorry for the misspelling and other things I'm french)
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