I found out there was a problem last week when a friend had issues signing up. New accounts are delegated some voting power by the @steem account. The problem is that this account keeps running out of available SP. It gets topped up via the main @steemit account, but either this is being done manually or the automatic process is not working. According to this issue there is a fix for this.
The other issue around this is that users get error messages that will not mean much to them. I don't see too many error messages these days, but if I do it should make it clear if I did something wrong or if there may be a Steemit bug. I would hope that errors get logged automatically, but we may need a simple way to report them. Not everyone will be on Github.
The new user experience needs to be optimised as every one of them is valuable. A bad experience may put them off. I know it's on the roadmap to give them more guidance at the start. I know some other sites do this well by popping up tips on what you could be doing. Steemit can be confusing for new users and a few hints on how to create a post (adding images, setting good tags) would go a long way to easing them in. Ultimately this information needs to be multi-lingual as not everyone can read English well.
There's a Learn More button next to the Sign Up that takes you to steem.io. That site is a little light on detail and some of it is out of date, e.g. about reward periods. I think a link to the FAQ would be better.
I'm obviously a Steemit enthusiast, but I have concerns that we will get a sudden influx of many new users and will get bad publicity if they have lots of issues. Some of them may have a high profile elsewhere and a bad report from them won't help. I think that a few simple tweaks could make it better. We cannot expect a full overhaul of the site design in the short term.
Steem on!

Mine cryptocurrency in the cloud at Eobot, including Steem. You can earn as you chat using WowApp. If you use these links I get a small reward. You can recruit others to do the same.