1) Dramatically reducing the size and scope of the speech rules they implement to something akin to "If the speech is legal in a country, then it's legal on Twitter" would reduce technical and operating complexity. Between developing the technical infrastructure to automate restrictions and bans, to having staff trying to judge all sorts of petty bickering between groups trying to take advantage of the rules to report and ban their rivals, I feel like Twitter is wasting a large amount of resources on stuff that they shouldn't even be trying to do. A smaller team could focus on the essentials: removing illegal content and responding quickly to actual issues of safety (stuff like death threats that might pose an imminent harm). Hell, I feel like Twitter is so involved in trying to get involved in Internet drama and disputes that they currently do a mediocre job on actually dealing with genuine safety issues.
2) I realize that the infrastructure to run a site as large as Twitter isn't trivial to maintain, but for a site that has so few real user-facing features, it's kind of surprising that their technical team is so large. If somebody just laser-focused them on a clearly defined set of important features and policies for the business to execute on, it seems like Twitter should be able to move much faster on the handful of things that are core to their business.