Sorry to hear about your rare blood disease Ingamar.
I agree, it is pointless to out your husband and is likely to lead to some damage. It is lovely that your husband has stopped attending for the time being and it gives you an idea of what he thinks is more important. Show your appreciation and hope that he keeps it up.
You may be walking a fine line but you could ask him to stop this elder (or anyone else) from visiting. In the meantime use TTATT (the truth about the truth) so that he doesn't become fully brainwashed again.
Some ex-jw's feel guilt for having left and are not 100% sure that the JWs are not the true religion, you need to concentrate on this aspect. An excellant book is Crisis of Conscience written by an ex Governing Body member and sheds a lot of light on the religion as well as removing that guilt feeling.