1. If you have your course accreditation certificate, then your additional theoretical knowledge requirements are as you state and you will be exempt the radio practical test.
2. How long to convert onto a different SEP Class aeroplane will be entirely up to you and the Club. You will obviously need to cover general handling, circuits etc - probably 2-3 hours minimum plus some solo? You probably have not covered 'precautionary landings' (forced landings with power) before, so you will need to be taught these as the Examiner may require you to fly one on your PPL Skill Test.
3. You will have to have completed a total of 5 hour solo cross-country, including the Q X-C, before you submit your licence application. This must all be completed on SEP Class aeroplanes.
4. The PPL Skill Test includes a navigation section, including some use of radio navigation aids. The aircraft used for the test must therefore be suitable for this purpose.
Historically, we have noted that many ex-EFT pilots are rather weak at VFR navigation and have a tendency to feature-crawl on the 1/4 mill map. Some have been unable even to plan a basic navigation exercise using a Dalton computer. Still-air timing and MDR drift are not accurate enough - you must know how to use a navigation computer. You will also be required to produce a weight and balance calculation and a take-off performance calculation for the PPL Skill Test.