My totally non-legal (and British) viewpoint is that this is a non-legal person trying to write a legal and binding contract and failing badly. It's ambiguous and quite unprofessional, and frankly it won't work. Even the title ... for sound contracting is odd.
It also fails to take into account fairly basic scenarios. Some terms I've never seen here - exhibit? What exhibit - if it's a rider to the contract then say Rider A. "equal to the manufacturer's operating specifications" is gobbledegook. In the next section you use the term 'may'. This word means might in some contexts, so load in may commence at 2pm, but if you mean 'will' this is a decider. Why put the end time - we all know the shutting the vehicle door is dependent on far too may variables to make a real time accurate.
In the list you use the format 4 x Carvin, then switch to 6 of the ... which is odd?
In English contracts, we'd probably have a problem with 'buyer' are they actually buying anything. Buying usually revolves around transfer of ownership?
Your request for payment BEFORE the show would not work with me, I'll happily pay you at the end, but if you were dreadful and ruined the event, I'd not be paying before, and many clients would not actually have the money until the box office was counted and collated. You then allow payment by check? In the UK cheques are dangerous and we don't take them as 'payment', just a promise.
Our electrical requirements here are broadly similar, but experience shows many venues pay little attention to it.
Parking - very rarely a smooth one - and contracts and riders usually specify We require parking for 4 vehicles (Mercedes LWB Sprinter type) within Xm of the load in door. If this is not available contact us immediately on 12345.... This always seems to work, sometimes with a followup.
Your request for food makes sense, but shorts and caps? Amateur hour I'm afraid.
Your statement that if anything in the contract is illegal, invalid or unenforceable made me smile - again, just silly.
I can imagine why you have put these clauses in, but you need to give this to a real legal person to convert it into something that would stand up in court.
Judge Judy would be in hysterics reading some of this. It's not your fault, you're not a lawyer, but I would never, ever sign that. Far too many of the terms are really saying we need this and if you wind us up, we walk out and you have already paid us. People just won't accept it. My lawyer friend said you always ask for what you require, but give them the option to negotiate or at least, say it's impossible.