DS eating habits at nursery school ... need advice

DS is almost 7 months old and started nursery 2 weeks ago. DS is EBF. We have started with solids and are doing baby lead weaning. The school was informed and fully on board. I dont pack a lot of food as EBM is supposed to be his primary source of nutrients. At home he plays with his food, explores the different textures, smells and tastes. I can honestly say that he hasnt "finished" anything yet. He loves certain things (watermelon, steak, avo, broccoli) but we've only had one poo that we could see he swallowed some watermelon.

On his daily feedback sheet, his teacher writes "food: ate some" or "food: ate everything". I didnt think much of "everything" (her interpretation of "everything" may be DS mushing his avo to pieces & smearing his face with it) until she wrote it twice in row.

So this morning I asked her what she meant by "ate everything" and she said he finishes everything I pack. Now, it isnt a lot, eg. 1 cucumber stick (8cm long, quarter of a small local cucumber) and a small potato & mozarella cake (size of DS's palm). She says it takes him 20minutes but he finishes it all. Sometimes he gags, but he spits it out and continues eating. (There is a nurse on duty and DS's food is such that he only gags - I'm really not concerned about choking.) Then a teacher's assistant piped in and said she gave him some yoghurt the other day because when she fed another boy his yoghurt, DS moaned and seemed to want some.

I didnt say anything but when I arrived at work, and had some time to think about it, I realize I should have said something.

(1) We're starting out with solids so I'm writing everything down that DS eats/tries in case of an allergic (or other) reaction. If she gives him yoghurt - that I didnt pack - what happens if it's sour or he has a reaction? Am I wrong to want to ask them not to give him anything that is not packed by me?
(2) I do not want to wean him off milk / breast too soon and because we follow BLW, we believe "food is for fun until one" but 2 days now his EBM bottles have come home with 40mls left over in both. He is not drinking his milk because he is eating so much. What am I to do or is this normal?

I'm a first time mum so unsure as to how things will progress when solids are introduced. I just didnt think it would take 2 weeks for unfinished milk to be sent home.

I dont even know if this post makes sense!

TIA