Yeah, Reddit's weakest link is its moderation tools or really, lack thereof. The mod tools were really written for a much smaller site, and hopefully this infusion of cash will let them hire devs who can make it their mission to make the mod tools useful.

Granular abilities - like the ability to give someone only the power to delete comments, or only the power to tag titles or something.

Restrict posting from new accounts - force accounts to be X days old before they're allowed to comment in a given subreddit.

Exposing the IP's of users to the mods - Most trolls/spammers aren't going to with proxies/whatever to get that many IPs, so exposing this is the first step to bans, which leads to...

Better bannning tools - even 4chan has good banning tools, why can't Reddit?

I spent all of 5 minutes on this so I'm sure a good developer can come up with a super useful list of tools, and them write them.