Hey Viking.   
Though the A10c has been around for quite a long time the tutorials can be a bit fiddly now and then. (Though update is in progress as i heard for this great module.) This being said i found that these so called bugs are not necessarily gamebreaking.   
Here are the so called workarounds i used when i ran into these kinds of problems:   
- dont push any buttons that are highlighted until the tutor finishes the instructions (voice wont jump) 
-  let the tutor finish what hes saying and press buttons highlighted after (this way the game will recognize u actually did the changes) 
- if the game didnt acknowledge the button change u just did, change the button back to its original position and then to the desired position ofter the guy stops speaking (ex. your TACAN problem) 
- try to match the instructors asked airspeed (this messes up weapon employment sometimes)   
Having all this in mind dont neglect that there is a huge book for the A10c :D and a lot of tutorials on the net (as the others pointed out). 
And not least Baltic will come with a new tutorial campaign soon hopefully :DD   
Hope this helps.