durp

Hey guys, so I got an issue. A few months back I bought my first 240 from craigslist (probably my first mistake right there) for 4500. 180k miles on it. Stock KA24e engine, basically stock everything else (found out later the cat was taken off & replaced with a welded resonator). It was imported from Canada years ago. So before I could get it registered I needed to get it smogged. Took it into nissan to see what they could find & fix. They "fixed" the timing & a few more things I don't remember (the papers are buried in my folder). So I took it to the state ref for smog & failed. Here's the list they gave me:
Air Injection System
-Install/Repair Vacuum Hoses/ Properly Route
-Install/Repair Air Switching Valves
AIV control solenoid is broken and vac line missing. Replace solenoid and hook vac lines up correctly

Exhaust Gas Recirculation Valve(EGR)
-Install/Replace Vacuum Lines
EGR Transducer line pinched off, use correct hose.

Misc. Emission Controls
-Check/Repair High HC Emissions
Check HC's emissions after repair. May change readings. Emissions close to failing.

-Other
Can be tested in the field after repairs per underhood label to US EPA. No label to be issued.

Timing
-Check/Perform Timing Functional
-Set Timing/Idle to Factory Specifications
Idle speed high. Set timing and idle speed to factory specs.

That's what the state ref gave me after I got the repairs from Nissan... I cannot get it registered unless it is smogged, so I'm basically sitting here with the pink slip in hand as my fees keep rising...
So here are my main questions: Could I fix all of this myself? If so, how much money would it cost? Do you think it's worth it? Keep in mind I'm only 18 & only have average mechanic knowledge under my belt.
I've talked to people at the DMV, AAA, Smog Stations & they said I have the right to sue the guy who sold it to me because the smog papers were out of date. Even the guy at Nissan told me (after I got the 240 "fixed" by them) the car is a "grey market" item and it's illegal to be sold & I should just try to sell it to some drifter or part out guy.... But I can't sell it without the registration fully in my name...
If you guys could give a kid any tips that would be much appreciated. Thanks.