Re: 1000 vs 2000
I think it kind of depends on the year.
The pickups is the most obvious: V Series in the 1000 and DiMarzio/IBZ in the 2000 Series.
1000 Series are always basswood and always painted. There has been more variety in the 2000 series. There have been mahogany and ash models, neck-thru models and models with veneer figured tops. There have also been dots, two types of sharkteeth and offset dots on 2000 Series guitars. Some of those varieties were not sold in the US.
In 2008, the 2000 and 3000 Series switched to Edge Zero while the 1000's stuck with the Edge Pro. 2000 Series was eliminated entirely with the exception of the RG2228 in 2009.
The most direct comparison would be 500 Series vs. 700 Series from 89-93, when both of those models were sold, although after the 700 Series was discontinued, there were 500 Series that had veneer tops and sharkies.