Hi!
Thank you all for being so helpful on my previous questions! I will be getting a full carbon bike in a few weeks, I currently ride with shimano flip flip mtn bike pedals as I had them on my mountain bike already and put them on my aluminum road. They are super heavy though, I would like to stick with SPD's as i'm still pretty new to clipping in and out.

Is it ok to ride with mtn bike pedals on a road bike? I know shimano makes a double sided spd? I like the option of mtn bike shoes as sometimes where I live you need to walk a bit.

Someone gave me a set of speedplay pedals which i'm reluctant to put on my new bike (would have to get new shoes etc, and they look scary to get in and out of...)

So to nutshell:
1. Can I ride my new carbon with mtn bike pedals double sided a lighter pedal? and if yes, which pedal would anyone recommend?
2. Would it be better to use the speedplay and get say Sidi shoes?, how hard are speedplays to unclip? Still worried about losing my toenails, do Sidi's come with a wide toebox?

Thank you in advance!