3 questions re: Rega RB 600/RB 1000

I have several questions regarding RB 600/RB 1000 tonearms.
I would appreciate your help in answering them.
1. I have RB 600 tonearm that i just mounted on Michell Gyro SE.The tonearm was used for 7 or 8 years on P25 table with dialed weight 1,7g.The slider under the tonearm (is it anti-skating?)with 0,1 &2 positions was on 0 all these years.Could it somehow messed up the tonearm bearings?

2.Towards Christmas i will have around 2k to burn on upgrades.Should i go for RB 1000 arm or should i just keep RB 600 and put 2k towards a better cartridge.Right now i have 3 cartridges,all of them are under 1k:Dynavector 10x4,Shelter 501 and Sumiko Blackbird.
Which upgrade will be better:rb 600 with new $2000 cartridge or rb 1000 with my existing ones?
3.Does RB 1000 has the same wiring as rb600?Does it have the same cheap Neutrik connectors ?How big is the step up torb 1000 sounwise?Thank You very much.
The slider set at O will not have hurt the arm it should be set to the correct anti-skating force.Usually this about the same as the tracking weight.Maybe the RB1000 might be the better upgrade but I think rewiring your RB600 could be just as good.The cartridges you have are good also.If you want to spend that money I suppose the RB1000 is the way to go.I think the RB1000 from memory has the better wiring and is the top of the range Rega arm.
Dear Overhang: I agree with Stefanl. The 1000 is a great tonearm and I think that you could have a serious improvement in the quality sound reproduction of your cartrdiges. The 1000 can be your last tonearm for ever.

Regards and enjoy the music.
If you like Rega arms there are also the developments that Origin Live has done with the basic RB250.Here is a link http://www.tonearm.co.uk/index.htm Some of these arms could well outdo the RB1000.
The Rb-1000 has a three point mounting system that is different from the screw/nut arrangement on the RB600. You may need to have your armboard drilled for the RB-1000.
Overhang. You may want to consider an arm other than a Rega 1000 since you will need to replace the armboard anyway. The Graham 2.1 and SME 309 both retail for about the same and IMHO are better arms.