Can I wire directly to the USB port and connect it to a microcontroller?
no, (well, not easily), you'd need to write a USB layer and driver in software on the micro so it could talk USB to the FTDI chip.
There's no point in doing that, its extremely complicated for no real reason.
I mean it should be connected to a real usb port to work as a COM port, or if I wire up to usb lines of it (Well this is using a FTDI chip) will it work as a TX/RX ?
Ah, do you mean if you have a second FTDI chip and wire them usb->usb ?
na, i'd be very surprised if that worked.
AFAIK the chip is a usb device only, it can't function as a usb host.
For USB to work there must always be a host and a device.
If not, I think if I find the TX/RX pins of its microcontroller and connect that pins to PIC?
Yes, that should work fine, but you'll probably want to disconnect the existing microcontroller TX pin.
Otherwise your PIC will try and fight with it.
Although, i guess it may work without that as long as the existing micro is in reset state (not running) since the pin probably goes to highZ in that state.
Also you'll want to check the logic levels of everything involved to make sure you're not trying to push 5V into a 3.3V device, or to handle it if you are.