Throttle Body and Throttle Position Sensor, ...OK....A Few More questions Options

[Craigers17]

So I recently bought a 914 and have only driven it about 3 miles. The accelerator pedal is very sticky and unresponsive. Today I took off the pedal board and disconnected the throttle cable on both ends. I think the pedal is being restricted by the cable, so I intend on installing a new one. However, it seems the throttle mechanism on the throttle body is also very tight and unresponsive upon actuation and release. So, first issue, I think replacing the cable and possibly having the throttle body rebuilt might fix this issue.

Second issue, it actually idles pretty well, however, with the throttle cable disconnected, if I give it throttle manually, it immediately tries to die. Occasionally it will backfire, but rarely will it rev with rpm's increasing. I realize at this point it's probably to early to diagnose problems, but any idea if this could be a symptom of a faulty TPS or throttle body?

On a side note, but more disturbing, is that while troubleshooting this whole situation, I took off the air cleaner and found it to be rusty and wet....the filter was soaked. So I've put the situation on hold for now while I clean up the air cleaner housing and get a filter.

Any input on any of this would be welcome....obviously I'm no mechanic, but don't let that stop you from making me feel like a dumbass...especially for not checking the air filter first thing. I've enclosed some pics of the pedal area, throttle body, and plenum area.
Thanks in advance.