OK...no legal representation is going to cost you on this little excursion of yours and you could be picking up the whole tab for this as well...
Now...more advice about your 4 questions;
#1...NO
He has a right to be there, as does his legal representative, while you question these witnesses.
#2...If you think you can prove this...go right ahead.
But your quest to prove witnesses don't belong may not help your case, especially if you fail in this attempt.
Best to stick to the relevancy of
your case and not worry about his witnesses. If your case is strong, the bearing of his witnesses will prove themselves out.
#3...Ummm..Ok...And yes, too much Matlock.
Once again, the relevancy of his witnesses will come out in court. Whether they lie or not, or if the were coerced or not needs to be proven with evidence, not because "you feel" it.
#4...Yes
Taped conversations may be allowed, but don't count on this alone to win your case.
Remember, small claims court isn't like criminal court.
Here's a good lesson from
http://www.isthatlegal.ca/index.php?name=evidence.small_claims_court_law_ontario;
"Evidence" is the raw material which an judge or adjudicator uses to reach "findings of fact". The findings of fact that the evidence generates are - for all their flaws - "what happened" for all intents and purposes of the legal proceeding. If you do not agree with the fact-finding that has been made (or even if you KNOW it to be wrong), recognize that the rules of evidence are the best rules courts know of to reach the necessary goal of fact-finding.
Remember as well that the "standard of proof" for fact-finding in civil legal proceedings - as opposed to criminal proceedings - is "balance of probabilities". So if the court hears directly contradictory evidence from two different witnesses, it will look to surrounding circumstances, other evidence of the witnesses, demeanour, documents - whatever is available - to see if there is some reason to prefer the evidence of one witness over the other. The evidence that they believe MORE - even if it is only slightly more - will be the evidence they hold as true - or to be a "fact".
This same standard of proof, sometimes referred to as "more likely that not" is also what the court will apply in deciding the outcome of the entire case. Recognize that is not a standard of certainty - it is just the best practical standard that can be applied and still resolve civil disputes. Another way of saying this is that all other systems are worse than this one.
When assessing a case you should try to distinguish between 'facts' and 'law', as lawyers commonly do. "Facts" are the raw material that are then inserted into legal rules to determine an outcome. If it helps, think of the relationship between facts and law as a bit like algebra, with facts being the variables and law the "if, then" equations that the facts are fed into.