You all need to define Tropicals as versus Sub-Tropicals.
Citrus, is not tropical, Madarins, can grow here, but are not tropical.
Serissa is able to handle zone 7, as is Sageretia.
Fuiken tea is a puzzle, probably zone 9.
Southern Chinese elms probably to zone 7
When we shift something from the UK, we have to do deep research to check for dormant states. In the UK what all the above might have is a greenhouse, unheated and a plastic covering, zone 9 to 8.
Bougainvilleas, are Sub-Tropical but will adapt easily to down here, as does crepe myrtle.
J.B.Pines are zone 10 to zone 7?
Ficus, hmm, those from China, zone 9, those from down here zone 13b.
True tropicals are listed as limited to 55 deg.F, after which they damage.
However we have so many decoratives from the Sub-Tropics, it is hard to say just what they need save, shorter days and lower high temperatures for so many months.
Happy Growing.
Good Day
Anthony