Help please with snagging issues (inc pics)

[ginghamstarfish]

Looking to buy a bungalow which is 18 months old. Just had a snagging survey done (thought traditional survey was not suitable). Some minor issues but the big one is quite a lot of cracks on the exterior - in the render but also on the stone lintels and cills. Also wondering why on some windows these are in two pieces - surely a lintel should be in one piece to start with?
The house should be covered by the developers' two year warranty period so do we just ask the sellers to have these matters sorted? Does it require a structural engineer? We don't need a mortgage btw. Can't talk to solicitor till Tuesday so just trying to sort out what we need to ask for. Any help appreciated!
pic 1 - several like this - stone window cill, central join, mortar cracked
pic 2 - stone lintel - central join, mortar cracked
pic 3 - the worst = stone lintel cracked, crack continues into render

That might be plaster over a metal lintel rather than stone - metal is cheaper.

I would ask the home owners what they done about it and how receptive the builders have been.

im in no way qualified in anything building related however I have had 2 newbuilds and one had this issue and a few of the neighbours on my estate have too so I imagine it’s quite a common thing. It was an easy fix both times they fill it with something and the crack is no longer noticeable.

I know render and plaster can crack when drying out, it's more structural issues I'm worried about.

I'd be wondering why the current owners haven't got it sorted yet and why they are moving out so soon. I've had a new build and the list of snagging issues was endless. I'd not buy new again.
However, we had large cracks internally and was told it was 'settlement'. They replastered and no problems in the years following.

Yes we did wonder why they would move so soon, they say due to husband's job changing.

Those are not lintels, the lintel will be out of view, those will just be large decorative bricks effectively. If it was a lintel it would have failed a long time ago!
You can try to get the building control structural documents, either from the builder or the inspector, if you want more information, or could instruct a more invasive inspection, but I am surprised they are concerned about that.
You can get it repointed if you like but the mortar colour won't match any more.

One and two looks like drying out and settlement. Three would worry me more and would want investigating. Don't rely on the builder though. Get your own independent surveyor if you want to pursue it

Thanks, yes I would be worried about the cracked lintel even if it is just a decorative outer, surely a solid piece like that should not crack due to settlement. We will send this to the sellers and ask them to get the builder to sort it as it is still under the 2 year developers warranty. Not sure how much to trust him to do it though, being cynical, but as it is under warranty we don't think we can insist on an independent builder.

Does it not have an NHBC 10yr warranty?

Yes, but the builder covers the warranty for the first two years.

Those are just decorative bricks. The lintels would be out of view. You should ask for building control documents, either from the builder or the inspector. Also, what was mentioned in the snagging survey?

Other options would be to have an invasive inspection, or at least to have a monitoring device installed for the crack. Would be possible that you don't have lintels and the above wall is just sitting on those decorative stones and the UPVC window frame?