ETX90 any good for astrophotography?

[mindburner]

Got the Skywatcher 300p flextube a few months ago and with the addition of a GOTO handset it has been simply stunning. Super views of nearly everything I have looked at. I even saw the ring nebula.

My now not used much ETX90 has been mounted to the skywatcher AZ Goto mount.

I know from the forum that an EQ mount is really needed for serious astro imaging. I was wondering if the AZ mount may suffice for now. I have a few Q's

I have a Nikon DSR and T mount. I think I need another tube adaptor for the rear of the ETX. Can anyone confirm?

Is it worth getting a EQ mount and will the 90 do a decent job at imaging, as the optics seem not too bad if a little dim for observing. I know a new OTA would be best but I'm still paying for the 300P:)

I have a Philips web cam too, but the images are very magnified. Can I reduce this in some way?

many thanks