mono cartridge vs stereo

Guys, I have a single tonearm available to me, and it is set up for stereo. I've got two questions:

1) When using the Y adaptor, do you need two Y adaptors, one to sum the L+R channels and one to redistribute them back to L+R outputs?

2) If you definitely don't have a mono cartridge, is it better to buy stereo re-issues of mono LP's?

Oh, and two other things. I'm assuming that with the Y adaptor approach, you're not just taking one channel and splitting it into two. That you are in fact blending the two channels and then distributing the blended signal to two RCA's.

I should also add that I have an outboard phono preamp. I assume that I should place the double Y adaptor device between my phono preamp and my linestage preamp?

There is no VS if you have many mono records you get a mono cartridge as well.

EBM - what you are saying is absolutist and contrary to what others have written. It seems you can use the Y adaptor approach, but you lose some fidelity. How much, I don't know. But most people don't have the capacity for two tonearms or the ability to quickly swap cartridges.

Do what you like i don't really care!!!