Terry, sorry to say, I think the Nord Stage is the wrong board for you, if you want just one board.
It sounds like, other than light weight, you really want a kind of updated version of your old Roland, which isn't what the Nord is. Other than light weight, these are the main things a Nord would give you coming from your Roland...
... better pianos
... better organs
... better ability to create/tweak synth patches (through knobby interface)
... ability to work with your own samples (maybe your Roland can do that? not sure, but even if it can, it was a bear on older boards)
... wide range of sampled "vintage" keyboard sounds (mellotrons, string machines, fairlight, etc.)
none of which you expressed any real need for. Does anything there really tempt you?
Meanwhile, the things you talked about wanting are not really there...
... you like a wide range of synth presets that will get you close to sounds of popular songs, without having to tweak or program your own synth sounds... not a particular strength of the Nord
... strong acoustic instrument (sax, brass) emulations, also not a Nord strength. These kinds of sounds are in the Nord to cover the basics or fill in in a pinch, but they are not the quality of what you'll find in many other boards that employ multiple velocity samples or alternate articulations.
Every board has a balance between what it does really well and what it doesn't, but in this case, I don't think you care much about what it does well, and you care a lot about what it isn't the best at.
As LudovicVDP said, within limits, you could sample your favorite Roland sounds into the Nord, but that's a lot of work to still end up with something that will still generally be not as good... you'd be better off getting a board that does what you need in the first place.
Picking up from what Rusty Mike said, for the functions you want in a more modern and lightweight board, you're better off looking elsewhere. Assuming you want to stick with 7x keys, the forthcoming Roland FA-07 is an obvious choice, as it will probably even already have many of your current sounds in it. The Kurzweil Artis7 would be another contender, with good acoustic instrument sounds and lots of patches that are designed to emulate the sounds of popular songs (especially since you can also use their computer editor to load in all the sounds of the Kurzwei PC3 series). Kronos has been mentioned, it's also a very strong board and includes lots of patches for popular songs, but it has a bit more travel weight esp. if you want 7x keys (their 7x uses a weighted action; there's also a new 88 key LS model that has a lighter action, but the board is still a bit on the big and heavy side... worth considering, though). These are all designed to be able to do splits easily, which you subsequently mentioned as something else you're looking for. There are some other possibilities, but I think those are your three best choices.
Okay, now for something completely different... Whatever you get, if you get a non-Roland and find yourself missing some of the Roland sounds, but don't want to take two keyboards (or deal with the effort and limitations of sampling those douns), you can add a Roland Integra7 module to any of the other boards, and have access to a huge Roland library of sounds as well. So if there's something about the Nord that really appeals to you, you could get the Stage and add the Integra to pretty much have it all. Jasonbass32 just talked about doing this at
http://www.norduserforum.com/post87280.html (and you could also add the Integra to any of the other boards mentioned here).
As for not wanting to try things out locally and end up buying over the internet, if you know you're going to buy over the internet anyway, my advice would be to try them out by buying over the internet from a place with a good return policy. Yeah, return shipping for anything you don't keep will cost you some, but it's usually not so bad, and you're also getting the benefit of having days and weeks to play with something to decide if it's right for you, rather than just minutes or hours. If your credit card can handle it, you could even order a few different boards, try them all for a while at home, go back and forth as much as you like, and then just return the ones you decided not to keep.