The main issue with all of this is the railway insisting on using hopelessly outdated gear to collect its revenue. The fact that such a big organisation has major problems accepting a sizeable chunk of the population's perfectly legitimate debit cards is downright ridiculous. Much of the kit we use at our depots is in a bad state, and I presume it's the same elsewhere, so it's clearly high time that a new version of Avantix was introduced.
The main issue with 'swipe and sign' transactions seems to be that the TOC can end up with something called a 'chargeback', which essentially ends up costing money rather than making profit out of the ticket sale. Having said that, most of our Guards will use swipe if need be, and simply enter an authorisation code of our choice (you can't go wrong with 0000!), and management don't appear to be unduly bothered. At the other end of the scale, SWT Guards are instructed that any swipe and sign transaction must be authorised by telephone without exception. What is irritating is that things seem to have been changed fairly recently so that the machine is set up to decline any swiped card that wouldn't process through chip and pin, so swiping is no longer an alternative since you already know it won't work! Hence there are certain instances (dodgy looking individual pulling out the inevtiable green Lloyds etc) when I will swipe straight away, in order to ensure a ticket is issued.
To refer back to the OP, the skewed/wonky print on some tickets will simply be the ticket feeding through the printer at a slight angle, which is often caused by the previous ticket having twisted when being torn off. The blank tickets are all joined together on a continuous stack and are then torn off individually as required once they emerge from the printer.