Are there any scenes between the 2:00:00 and 2:11:00 mark of the Special Longer Version which are not included in the DE?
There are YouTube videos comparing theatrical version and DE and the theatrical version and SLV . Not a direct comparison between DE and SLV but the information you are looking for should be there.
The DE of TMP was just updating the effects, in fact I would say that was secondary, mostly fixes and some enhancements. But it also fixed some of the pacing issues of TMP. So some scenes were removed and edited for pacing purposes. Sometimes directors cuts are not necessarily the director's preferred version, sometimes the director intended on the theatrical version to be their definitive version (i.e. Alien by Ridley Scott). But in TMP's case, Robert Wise never seemed entirely satisfied with the theatrical cut, or even the special longer version released on VHS. I think that's why it's called a Directors Edition instead of cut because this was a version Wise worked on to fix what he saw were some flaws (though not necessarily a final edit that he would have done in 1979). Pauln6 probably has the best place to find the differences though.
This is probably unrelated to the topic, but while the DE has a running time longer than that of the theatrical version (136 minutes vs. 132 minutes), it uses the longer version of Ilia's Theme for the overture and the end credits are slightly longer (the TMP theme is looped in the first half) to include the folks who helped put it together.