In article ,
wrote:

So let's say I'm inbound to Teterboro from the west, doing 250 kias
below 10,000 in descent. Atc gives me a radar vector, and clears me
to maintain 4000 feet.

1, Do I need to slow to 200 kias at some time?

Almost certainly, yes, at some point prior to when you flare :-)

I suspect you're thinking of the restrictions imposed by 14 CFR 91.117. It
imposes three basic speed limits:

A) 250 KIAS below 10,000 MSL

B) 200 KIAS below 2500 AGL or within 4 NM of a Class C or D airport.

C) 200 KIAS beneath Class B airspace.

A requires the administrator to waive. B requires ATC to waive. C is
non-waivable. Minimum safe airspeed trumps all those. That's usually only
a factor for a heavy jet right after takeoff.

In your case, B is probably what applies. If you want to exceed 20 KIAS,
make a request of the controller.