Highlight of table,procedure ....

On left where is list of tablec, procedures, ...
the active object is higlighted by very pale gray, almost unnoticable.
Can that be changed to stronger color ?
Although I think red dot icon of somethimg near it would be great.

Or name of object surrounded by 1x black rectangle, even better.

This color is set by your Windows Aero theme. Just like it looks in your Windows Explorer. You cannot change that in HeidiSQL directly. Just use a different Aero theme, please.

This is bad idea (you mangle other programs setting which you posibly don't want to) should be enabled inside HSQL separately.

Besides- tryed that - my icon windows (win 7) which pops up when hovering mouse over taskbar disapeared . Lost a bi of time & couple of forums & had to restart to get that back.
Will never ever touch that again (-:

I'm sure you're also using your Windows Explorer, so I'm sure using Aero logic in other programs is not a bad idea.

Your icon disappeared? That was fixed recently. Update to the latest build and you're done.