merging stereo with ht, can anyone please help?

Up until now, my audio life has been easy. In my den, a HT system utilizing Sherwood Newcastle 1m-9080 5-channel power amp and AVP-9080R preamp. In my great room, a dedicated stereo utilizing a Grant (English brand) tube preamp, Acurus stereo amp and Dunlavy II speakers. Now, baby is on the way, den is mutating into nursery, and I am trying to blend HT and stereo, with decidedly mixed results. Here's the main issues:

What I'm planning on doing is utilizing the Newcastle amp for center, rear, and subwoofer channels, and my Acurus amp for the Dunlavy fronts.

1. I want to use the Sherwood Newcastle preamp for DVD source and my Grant preamp for CDs. Can I run cables from both preamps to the Acurus amp, and connect with a Y cable into the stereo inputs? If so, will any damage ensue to any components? What happens if I mistakenly play a DVD and a CD at the same time?

2. Can I run a subwoofer cable from both preamps to the subwoofer (M&K), and use a Y connector to input to the sub? If so, will any damage ensue to any components? What happens if I mistakenly play a DVD and a CD at the same time?

Any further thoughts/ constructive criticism welcome! Thanks for your help, oh great Goners.

Regards, Ben
run your pre/pro outputs for L&R into your two channel pre-amp. if the pre-amp doesn't have a HT bypass mode, simply set the volume to a known position (relatively high), and calibrate the pre/pro levels.

use the pre-amp for CD listening, and switch to a different input to select the AVP pre/pro for DVD (setting the volume to it's "calibrated" position)., if only I understood what you meant. What are pre/pro outputs? Are you suggesting that I connect my two channel preamp to my ht preamp, and make the two channel preamp a "source"? What good would that accomplish, since my whole goal was to bypass the electronics of the ht preamp? My preamp does not have a HT bypass mode. thanks, ben
CY has it right but I think you reversed the order of your preamps. Come out of your Sherwood from the L/R front main preamp outputs (hopefully that model has this feature) and run them into one of the inputs on your Grant preamp. Run your CD player into the Grant and the DVD into the Sherwood. Connect the Grant to your Acurus amp and you're set. I believe your idea of a 'Y' adapter with an a/b switch for your M&K subwoofer will work fine (down the road you can hook them both to a Creek obh 12 unit and get the a/b switching plus remote control for your sub).
You are going to have a mess of cables running everywhere though. Good luck.
Don't use Y adaptors.
Run the left and right pre amp outs from the newcastle to the tape in or aux in on the Grant. Try setting the Grant to 1/2 volume then experiment where the volume really should be to be balanced with the L/R and rears. You can either use the internal controls on the Newcastle or just remember where the Grant volume matched the newcastle.
This way, for serious listening, you can just use the Grant/Acurus/CD/ set-up. When using theater, everything will be on but ideally you will only use the newcastle volume, leaving the grant volume set at a pre-determined level.
Thanks to all who took time and thought to help me out. What a wonderful community Audiogon is, eh? I'm about to head into my living room, re-route a few cables, and benefit from your wisdom. Thanks again, Ben