Mount PC's HDD on Mac, with a USB from Mac to PC I was wondering is it possible to connect, a MacBook and a PC by a USB cable and then mount the PC's HDD/SSD on the MacBook?

Further more if this is possible, would there be any restrictions on the MacBook's side?, I know about lacking support for NTFS, but how about using programs such as Scalpel, and the Sleuthkit collection to restore deleted data, and such?
You can transfer files over WiFi or BlueTooth. For fast speeds you can plug both computers into a router via Ethernet cables and communicate over the network that way. These are the non-invasive approaches that don't require special cables or enclosures for the HDD you are copying from. You can also try a file sharing server like Samba that you run on one machine and use the other to transfer from. You won't need special drivers for NTFS if using one of these networked approaches.