why they needed clouds of incense -- the smell must have been horrendous

Amazing how things change with the times! I am sure you are correct BobY! But then in days of deodorants and frequent bathing we were told incense was used as it rises and takes our prayers to heaven with a sweet odor of supplication.
I think you are on the mark and we were fobbed off as the adults are sometimes wont to do with children.

Now as to : custom in courtrooms to have a bouquet or nosegay
The Shorter OED has no entry for nosegay, but Atomica does!
There is also a floral piece called a tussymussy which has to be looked up as two separate words -- it's a small bouquet of casually arranged flowers.
I like that word : tussymussy !
wow