Just trying to figure out how this one is relevant.
I have every single one of my abilities, including ones that I would never use, along with stuff like seeker droid, speeder, medpacs, bound with just the left half of the keyboard and shift + the left half of the keyboard. I don't have anything as far as 6 bound with shift (don't have shift+5 either, actually), and I don't use ctrl for anything.
Because comfortably I can't use any number keys past 4/5 (5/6 are a stretch) if I have to use ctrl or shift with them, my bf can use most of the top row with his enormous man hands. Shift is bound to Vent anyway, I tried to set it up to work with one of my mouse side buttons but the drivers for it are bugged and I couldn't find a fix so I just left it on the keyboard.
On my Operative I have 4-5 action bars worth of abilities lol, idk what class you play. I mostly only use the ones on the main two bars and the two little side bars I have set up either side of the second main bar. I bound two of my instant cast heals to my mouse side button though, that was a huge help.
I've got small hands too -- which is why I love my Razer Naga mouse. Might wanna check it out (or a similar product), made things worlds easier for me even though I am an excellent touch typist and can leave homekeys if I have to.
Efficiency aside, it was just way more comfortable for me too.
I have a Razer Deathadder, it has 2 side buttons. If I bought another mouse, I think I'd look into the Razer Naga Hex, it looks like its somewhere between the Deathadder and the standard Naga. Otherwise I'd look into a Nostromo for my left hand, but since I don't raid anymore and play in offpeak times on a PvE server so don't like my chances of getting into ranked WZs, I probably wouldn't bother for SWTOR. Maybe if I got back into WoW, but SWTOR's really spoiled me with its shiny character models and voice over quests and easy levelling and lack of hardcore grinding.