160,000 sounds like KM, equivalent to roughly 100,000 Miles. Beside being used, rubber does degrade slowly from disuse, 50,000 miles as a first point for inspection seems about normal (then check again every following service, then replace at any sign of wear) - i'd rather fork out a bit for a cambelt change and have my mind at peace, than risk it for a biscuit and potentially total the engine on the premise of "well some bloke on the internet says hes on his original cambelt after 200,000 miles, so mine must be fine for the same".
It's probably still a good idea to check it every now and again, it's easy enough to take the top part of the timing cover off.
As for spark plugs, if you're getting any sort of lumpiness at idle, it's time to change em. Instead of the usual OEM plugs (NGK), i went for the Denso IXU line, given i'm running hybrid turbo i went one stage colder (IXU24), but for a standard or stage 1 car, the IXU22 is the perfect replacement. Given that they're iridium tips, should last longer than the NGKs too. Avoid Bosch plugs.
Brake fluid is an essential thing to replace. A friends Rover 25 was suffering from awful brakes, one caliper was seized and the other side was bare metal! We replaced the seized caliper, and put in new pads and discs all round but the brakes were still pretty trash, figured we'd put the spare brake fluid to good use and flush the whole system, what came out was practically black! First test after a full flush and bleed, it went from having to stamp on the brakes to get any form of braking to stamping on the brakes and almost going through the windscreen!