Any east input for route out:
Henry, instead of turning right from Snaresbrook Road, just turn left and then into Eagle Lane. That takes you to an underpass under the railway line between Eagle Lane and Falcon Way.
Also, much more popular among cyclists than the route you've drawn via Chigwell is to take the B173 Manor Road/Lambourne Road than the A113. The latter has a lot more car traffic. It takes you a little higher up, but you can then drop down to Abridge along Hoe Lane. Even more popular is to carry on along Manor Road and then to turn left into Hook Lane (my favourite lane) and left onto the B175 Stapleford Road, then straight on at the roundabout for a short bit of the A113 London Road, then turn left just after the the M25 overpass to go along Tawney Lane. Hm, with the flooding yesterday and this morning I'm not sure how clear the latter is going to be, but it is rather lovely to ride along. You'd then hit your intended destination loop from the SE. (There's nothing really wrong with your route after Abridge, I just thought I'd show off my local knowledge. :) )