I think it's a good idea to prevent the downsides that come with a gambling habit, especially if it makes you feel bad. Cubes are gambling and RNG items, and often what you're gambling is your time and effort. There are other important things in this world that you can worry about, like making a living. That's always a great endeavor. Anyway, good luck to you and whatever you decide.
Ya. I agree that Shade is harder to fund. I funded maybe around 10bil in my Shade and I couldn't do much damage at all. Then I switched to funding a Kaiser with around the same funding and I was hitting waaaaaay more than my Shade.
Every class has it's "range threshold" I like to call it, before you start throwing in cubes and whatnot. Even perfectly traced equipment can really only get you so far in your range. Of course you'll want to perf all your equipment but even then, those are only additive increases to your damage.
Cubing, on the other hand, provides a potential (no pun intended) to increase your range by a far greater factor. I'm not sure which stats are multiplicative or whatnot, but things like %Stat, %Att, etc. will boost your range by quite a bit. Keep in mind though that it's not like one or two legendary cubed items are going to get you where you want to be, as that'll only get you the "average" range. Until you have multiple perfected items, and on the right ones, will your damage really seem to get you somewhere.
As for Shades, I hear they have pretty bad scaling. I'm not sure how this works out, mathematically, but that's what I hear from a lot of people. I haven't played the class though, so I can't be sure. Whether or not it's good though, if you like the class, just fund your character hard and don't compare your range to others. You'll get there when you get there.