No, printers are usually not worth it to fix. I would recommend recycling it.

No, fuse box fuses are of the screw in type. Plug in fuses are of a cartridge style that plug into the fuse holder which supports the fuse on either end of the cartridge.

That is impossible as it will alwyas stick out although you can use the GBA cartride holder to stop it

If its a cartridge style replacement filter(as opposed to a spin on), then simply unscrew the hex-head shaped holder with a crescent wrench...:)