First post here - hello!
I think the whole Smiler project has been rushed and mis-managed from the word go. I don't think there's a single cause for the opening date being pushed back to May, and likewise, not a just single cause for the recent delays, either.
Merlin seem to quite like building things to a tight timetable recently. I guess this keeps costs and disruption to a minimum, but it also gives them absolutely no wriggle-room.
With regards to the Towers Times article, the bit about the health and safety citations does seem to hold true as there's links to the reports on this, but although it seems it probably did valley (as there's been pictures of a used train being craned back onto the transfer track), I'm pretty sure the 'scrapes' they're looking at on the track are just wheel marks from the normal running of the ride. Some parts of the track look worse than others, but this is presumably just to do with the different forces on different parts of the track.
There's been a lot of work all over the ride over the past few days - trains being craned around, people working on the lift hill, they've been increasing the height of queue line fences, even the bins weren't put out until a day-or-two after the ride was due to open.
So as exciting as a train grinding itself into the track sounds, I think the reality is a lot more boring than that.
It will be interesting to see how this affects Alton Towers' attendance this year, and of course their takings. I feel a bit sorry for them, but it's the risk you take when you run to such tight deadlines with no redundancy. Building a coaster is a complex thing involving the park, architects, council, health and safety, the manufacturer, the construction crews (both groundwork and steelwork), electricians, landscapers, Studios North etc... all have to work in perfect synergy and every delay can be amplified further down the line, and I think this is what has happened from day one.
Incidentally, Alton Towers have updated their site to basically say it is "currently closed" as opposed to "will not be opening on [the next day]"