Hi Deadllama:
Yeah, if you are smelling faint hints of gas and you have a rough idle and your cannister has a disconnected hose, they could all be related. One of your photos shows a hole and crack in the plastic cannister...looks possibly like a rodent chewed on it...you can use some JB Weld adhesive or other epoxy type adhesive for plastics to seal this up. Was your other issue that you had a hose missing on one of the cannister ports? If so, just locate that hose and connect it back on if it has not deteriorated. If you cant find it, go to the Autozone website and check their tech section for what your emissions hose routing should be for your year and engine config truck...if you have trouble figuring it out you can just go to an Autozone when they are at a slow time and one of the sales guys should be able to come out and help figure out what the connections should be from the hose routing diagram...they also should have replacement vac hoses.
As a temporary cap-off until you get everything solved, you need to just follow every hose from your carburetor and make sure it is not hanging loose or leaking. If you find one that is loose cap it off with a golf tee or similar and you can continue to drive around until you fix or replace the cannister and/or hoses. If you only find a split or cracked hose leaking just tape it up temporarily with electrical tape. Inspect all your hoses that go to the cannister...they are probably so old now they are cracking and falling apart...all may need replacement.
Regards,
Henry