Rat Bikes! Pub Bikes Beaters! Frankenbikes!

Damage like scratches or scars to the spokes will result in a snap, possibly quite quickly. Just bending them is less of an issue, but I'd still check them all throroughly and replace any that were damaged.

Don't do this:

all you have to do is make sure the tension is about right by squeezing 2 spokes on same side together till it feels roughly the same all the way round.

That's for stress relieving wind-up in the spokes, not for checking even tension. You can check relative tension by plucking the spokes and comparing the 'note' it makes. A well-built wheel should have all the spokes on either side make roughly the same pitched 'ping'.