1. are all white bugs with tails aphids? Is there a situation where they may be symbiotic for so many of the tropicals these days have them but do not show themselves until a leaf is unfurled or until it blossoms ?

Welcome to the Forum!
White bugs with tails, living on tropical plants (indoors?), may or may not be aphids, but there's a good chance it's NOT a bug that's good for your plants.
Is there any way you could post a picture? A close up of the bug would be helpful, also a snapshot of the whole plant and pot.
It's best to positively identify a bug before either :
(a.) attacking it, or
(b.) deciding it is benign and should be left alone.
If it is a bad bug, there may be less or non- toxic ways to get rid of it. Identification is the first step, though.

Just to clarify, aphids come in a host of colors are sizes, but none that I know of have tails, at least not a centered, single thing we usually call tails. Most aphids have two little appendages called cornicles. They're distinctive for ID purposes.
https://www.amentsoc.org/insec....

Here is a phhoto to the bug in question. If not an aphid, perhaps mealy bug. It seems exude (or come from) cotton like substance.

Mealy bugs,, I think. Others who grow tropicals can help with control.