Apparently, it won't interfere with the PC slot, according to the link I just supplied.
Well, this information is incompete. A more precise explanation can be found on this page:
https://bigbookofamigahardware.com/bboah/product.aspx?id=987It says, if you install 8 MB RAM on the card, but set jumpers for 4 MB, then you can use the MagicMem program to work around the PCMCIA issue. But the memory will be divided into two address ranges and you loose 2.5 MB RAM.
Regarding your issues with CF cards: that the light stays on all the time is a well known issue with these CF-IDE adapters. It does not restrict the function.
And that the HDD disappears after a reset is also a known issue with Kickstart 3.0. Normally it happens with spinning harddrives, but sometimes also with flash memory. The usual fix is to cut the reset line of the IDE cable so that the drive's firmware does not shut down when the computer resets. Kickstart 3.2 should fix it, too.