Put Lidl’s £5 saddle bag (with a full complement of tools) to the test. If you don’t do the miles it is great value. Should get you out of a fix.
If you do do the miles you probably have it already.
Changing a tyre with the plastic tyre levers was hard work. The curved end just wasn’t up to it not pulling the bead over the rim. Best to invest another £1.50 in a nylon pair that will do the job.
I carry nearly 1 kg of spares on an Audax and look to reduce it further.
Hex Wrench is fine. Chain wrench should be fine as long as you have a spare link or two for your chain.
Two cable ties and some tape and possibly some folds of Gaffa tape and you should be fine. At least one tube and a decent puncture outfit should see anybody cope with a ride misshap.