Ok, first time round 'Pro' assistance can be well worth paying for, but you need to check and inspect *everything* you can before handing the job over to them, and make sure you observe and take notes.
Before my mast was first stepped, I spotted a cracked tang on the masthead fitting for the forestay that the rigger had missed when preparing the mast for storage the previous season and also a toggle below the furling drum with the wrong sized pin that had obviously been that way for a number of seasons. The toggle was replaced to match the hole size at the bottom of the furler and the one on the stay plate on the bow and the masthead fitting was reinforced and welded.
Inspect the standing rigging as best as you can. It really needs to be off the mast to do it right. Wearing heavy LEATHER gloves, coil each stay in a fairly large diameter coil and look for 'meathooks' (ends of broken wires). Any found is an instant fail for that stay AND the same stay on the opposite side which must be assumed to be the same age and had the same wear. If more than one stay has a broken strand, replace the lot. Inspect terminal fittings closely. any visible damage or if bent, condemn the stay (unless its a replaceable fitting like a Norseman or Sta-lock). Remember, wire rigging can look perfect until you bend it and a broken wire end pops out.
Check all blocks and sheaves, lubricate where appropriate and make sure that at least two masthead halyards are in good enough condition to trust with your life when you have to go up the mast.
I also replaced the VHF aerial, mount and lead (they'd lost the wind hawk off it and the mount was loose) and cleaned the lenses, contacts and connections + fitted new bulbs toall the lights up the mast. Replace the VHF cable if the old one is over 5 years old or of uncertain age or if there is any evidence of wear, damage or corrosion. The aerial itself is probably OK if it appears to be in good condition and can be swapped out in 1/2 an hour from a bosun's chair. Lights should be tested using a 12V battery (or lead from a car cigarette lighter socket) and a lead with clips you can connect to the wires or plugs and an in-line 5A fuse to protect against shorts,
If you know how to use a multimeter (and every skipper should), measure the resistance of every up-mast circuit at the plug or connector (from the (switched) 12V feed to the 0V return) with the new bulbs installed and record it in your maintenance log. Its a big help when fault-finding in future to know you *DONT* need to climb the mast! Also check the resistance to the mast itself. There should be no circuit. Any under a couple of Megohms has faulty insulation and needs fixing (except the VHF cable which may be grounded to the masthead via the aerial mount, If so it should read under 20 ohms to the mast and no circuit with the connector removed from the aerial and mount. Record all wire colours, plug pin-outs and connections in your maintenance log.
Masthead instruments cannot be easily checked. If you can disconnect the masthead unit easily, the cable can be checked wire by wire for shorts and continuity or if you can get the mast heel over your coach roof, you can hook them up and do a functional check.
You are paying these guys by the hour and if they find any problems will be paying them for repairs. They will obviously do a standard inspection of anything they rig, but will NOT do preventative maintenance unless you ask for it and having them do everything wont get you familiar with your rig which you need to be for your own safety. Its worth paying them to check and service (if required) the furler.