memcached is not necessary, you can run with --no-cache option, or leave with in-memory cache. Using memecache locally is not super usefull. libcurl (and pycurl) can be ommited, it should still work also. Pando shoudl be a requirement of *nbconvert*, but I agree that we can point out that it need to be installed. Not sure why you would need libevent-dev.

So I would try to de-emphasis that they are **required**.