Moreover, if the reps have fewer staff, they will probably rely more on lobbyists for research.

There's loads of ways to solve it though. Let them form groups and pool money to pay for analysts and staff as blocks or beef up the OMB to provide better faster analysis of bills and let them use those. The pooling makes a lot of sense to me because with groups that large you're going to have to form shared interest groups just to have reasonable length debates.

Not if actual experts get elected. With 30,000 reps you are going to get a wide variety of people elected many of who will know something about the world outside of politics.

If you include the staff there already are 30,000 reps, just that most of them are not elected. The current system is more like having 450 mini corporations running the place.

It might be cheaper, but it is going to be hard to organise.