Fiesta WS 2010 stalling, rough idle, rough drive

[jb1212]

I am having issues with my car Issues I get are:
* Stalling at lights sometimes
* Not holding a constant idle, going to 500 then 1900 often when out of gear
* Driving at 60kph in 5th gear the car seems to jump a little forward sometimes then want to pull back a little sometimes

Issue started around time I serviced it when I:
-Put new plugs in
-New air filter
-New aux and timing belts
-Adjusted valve clearances with new tappets

To troubleshoot I have checked:
-Air filter is not causing this (I ran car with/without air filter for a few seconds and it has the same problem both ways)
-No obvious cracks in air hoses
-Went to Supercheap Auto to check for error codes (I was not impressed with the outcome as they told me my car had lots of errors but could not give any error codes - I will go there again tomorrow and try another store)

Any ideas to further troubleshoot by process of elimination?

From reading lots of post in this forum I think it could be:
-Faulty throttle position sensor
-Faulty speed sensor (Ken_AUXR8 suggests this is not my issue so I will look at this as a last resort)
-Faulty sensor

Thanks for any help!