Any used boat can be abused or treated right, as well as most boats share components such engines, transmissions, V-drives, stereos, gauges, etc. To answer you question, a Tige can be a very solid, mechanically sound boat.
Wake size: what's your intended use, surfing, boarding, skiing, tubing? That hull was pretty much a ski hull, but Ive heard they're not too bad for boarding with some weight, but the quality of the wake really comes down to the perspective buyer's expectation.
Post up on
www.tigeowners.com, there are a few peeps with that boat and could probably answer your specific questions about the wake.