I'd generally agree with jon_1066 - and especially with regard to multiple combats. If you have two or more units in a position to attack one, you're probably going to grind them down pretty quickly using the rules as written. The sequential, "clash-based" DR system works well, I think.
On strength points, there is something to be said for "one figure, one die". That's the system that The Men Who Would Be Kings (by the same author) uses, and it may be an (even) better game. I'd try out DR "rules as written" first, but you could then do what you suggest: 12SP units roll one die per figure, and 6SP units roll two dice per figure. That should even out the relative strengths, so that your Elite Foot, etc., are still hitting very hard.
We tried this out when adapting TMWWBK to a sci-fi scenario, with space-marine types rolling two dice per figure. It worked just fine.
And then - as in TMWWBK - you could try units with bigger or smaller starting SPs. So you could pay the points for (say) 36 goblin light infantry and then group them in two units of 18 or one of 20 and one of 16 or whatever. That's essentially the Saga approach - buy troops in blocks of a given number but deploy them in units of whatever size you fancy.
I think the 3"/1" rule just depends on the size of your table. If you have plenty of room, a loosely applied 3" keeps everything nice and neat. If the table's a bit cramped, then 1" works fine.