4. Reducing time between comments? That's only a concern if you have crap karma, and it's easy to go from zero to excellent in a few days, so anyone making any real contributions will quickly find this is not a problem.
I assure you as someone with the highest possible Karma rating that it is very much a problem for those of us who use basic security and privacy measures.
The number of times I've seen the message "Slow down, Cowboy! it's been 40 minutes since your last post! Give someone else a chance!
That's a bit of a slap in the face considering APK spams the board consistently and apparently no one cares.
HTTPS: This is the only site I visit that does not use HTTPS.
Unicode: I understand the reason not to support every Unicode character. That could be (ab)used by a malicious person to screw up your board. But there is a subset of Unicode characters Slashdot could support so users can copy and paste the material they need to. The ones that are perfectly safe and cover 99% of the use cases we need.