No you are not being picky.

1/personally I think the tiling is the part of any bathroom installation that shows inexperience. The total cost is above average which is why you are expecting an above average finish although to be fair the pictures don’t show the entire bathroom and so the money may have gone on expensive purchases….. but none the less it’s natural for you to want a finish that is the same quality as the purchases you have made..

2/ some of these pictures show things that will improve with properly cleaning your new bathroom. You might try washing all the grout and leaving a cleaner room then taking a picture from further back and deciding what bothers you most.

I think most of us have some silicone in our homes that has a few bumps on it- but we don’t notice that generally so perhaps you should be pragmatic about this and worry about the parts that are really not right.

The tiles look like a natural product rather than porcelain- these are never as perfectly sized as porcelain and so some slight unevenness is to be expected and over time you won’t notice those things. I do however think some of the installation could have been done better.

3/ you should list the parts that you are really unhappy with- personally I think an experienced tiler would have cut the tiles at the bottom of the wall in order to leave more than a sliver near the ceiling……. Or they would have stopped an inch from the ceiling.
I think a more experienced tiler would have used tile edges rather than leave exposed edges of tiles- it’s weird that they have used them in some areas but not others.
I worry that the floor tiles are laid directly on your floorboards - there is supposed to be underboarding to stop movement and to stop the floor tiles moving or cracking.
The picture makes it look like he didn’t use a level- it’s very strange for tiles to not meet in the middle of a wall- it is slightly more acceptable if this happens in a corner.
Picture 49 shows an area that has gaps, bad siliconing, old parts of the room that should have been removed, covered or at least dealt with differently because this picture is the worst- it looks botched but a very close up pic is always out of context so perhaps there are reasons for it being finished this way.
It does seem like a few tiles protrude in places and this may be the tilers fault but it could be your walls- it’s disappointing they didn’t make you aware of uneven walls before starting the job because at that point you might have decided to pay a little extra to have a plasterer.

4/you don’t say what they have done electrical wise in the bathroom. Certainly in England you only need an electrical certificate if making changes to an entire circuit, if just changing a ceiling light you wouldn’t expect even a full time electrician to issue a certificate.

5/going forward you have to give this company the opportunity to put things right. You need to put your list in writing and be clear about what you expect to be done differently and give them a set time to do so- for instance you might specify the floor tiles being removed, the floor overboarded and then retiled. You might specify window cill to be removed and retiled using a tile edge for a professional finish. You might specify the square upright of wall to be retiled with the tile edges facing the sides rather than forward facing (because it’s easier to get a good finish on the bit that faces you if the tile edges are this way).

You should also satisfy yourself that the plumbing has been done correctly- fill the bath, check taps are tight and there are no leaks.

You then decide at this point if you trust that they will have the skill to complete the job in which case a part payment of the balance demonstrates your good faith since your deposit may not have paid the full balance of the goods you have received. At this stage you need to hold back likely £4,000 in case you need to buy additional tiles and employ a new tiler.