Thanks, haters, you’re the reason we can’t have anything nice
Nobody deserves to have their job made more difficult because of their gender (or sexual orientation for members of the LGBTQ community). Disagreeing with someone is perfectly fine, but you don’t need to be a hateful ass when doing it.
As to your proposed solutions, IP blocking would be a fairly easy solution, but it would negatively affect people who share a connection and would only slow down a dedicated troll who could use a VPN solution to connect through a different IP.
Up/down voting tweets of new users would leave legitimate new users in a sort of limbo that could prevent them from gaining any traction with followers and result in them leaving the platform.
Adding more humans to deal with security and abuse is a cost that Twitter probably can’t afford. In reality, there are only a small handful of companies that have the resources to address user complaints with a human in a reasonable amount of time.
One possible solution would be to require all accounts to be verified; this could be difficult to implement for businesses or “non-human” accounts, but it would be a minor speedbump on the road towards improved accountability for the words people post online. There is no single perfect solution, but something has to be done, as I know too many women who are subjected to hateful language when they post anything online simply because they are women.
Good luck to you.