as Clara.net handled your domain registration, they will have acted as your agent with the registrar - however, afaik, you can request them to transfer the details to a new registrar, such as 123-reg.co.uk.
this then gives you direct control over web forwarding, DNS management and name servers. (some registrars charge for these services, btw, be careful)
Your new host should be able to handle the email, most I've seen provide smtp - however I should mention my hosting company does recommend using the ISP's smtp server.
As for controlling the email server IP address, I think you will need more than shared hosting to do that, directly, but I'm not sure, tbh
