I've setup a full node and while doing so was wondering about the following:
1. Would it be safer not to use the same prominent ports as everybody else does (e.g. 14600, 14700, 14265). If instead the last two digits would be randomly changed, wouldn't that make attacks targeting the network more difficult or would that make things over-complicated and not worth the pain?
2. I see everyone is using UDP. Wouldn't it be safer to use TCP. As far as I understand UDP is nice for streaming (movies, etc.) but for security relevant data TCP is a better choice. It adds little overhead but probably causes less corrupted, broken and lost packages.
3. When it comes to adding neighbors is it 'the more the better' or is there a maximum number of neighboring nodes e.g. to maintain efficiency?
Finally, a suggestive thought which worries me a little: Many full nodes are popping up these days which is great! People follow the instructions e.g. available on github. However, there is no word lost there about basic security concerns related to running server e.g. how to setup iptables or fail2ban. I think this should be much more debated and communicated in the community.
EDIT: As for point 3 I just found the answer here where it reads that "[...]more than 9 neighbours is highly advised against, as it is harming the network".