9 Feral Kittens With Cat 'Flu. Am I Doing The Right Things?

I've been allowing these kittens into the house to be fed for the past few months and I've been keeping them in over night for about three weeks now. On Tuesday I noticed a few of the started sneezing and had discharge from their eyes. Since then I've kept them in the big front room, separate from my other cats. They are all about 6~7 months old

One of the little boys was really sick and drooling a lot so I took him to the vet. He was put on a drip for about an hour and given an injection on antibiotics for ulcers on his tongue. The vet gave me Ofloxin Ophthalmic ointment for their eyes and Ofloxin drops for their eyes and nose.

I had to syringe feed a few of them on the first day but they are eating by themselves now and drinking lots of water and chicken broth.

Any advice on how to use eye drops and eye ointment on half wild kittens? They'll let me pet them and when their eyes were completely gummed shut I could get the drops in without them noticing, but now that their eyes are almost fully open they see me coming with the dropper and hide. I've been waiting until they are asleep and sneaking up on them, but can only do one eye at a time that way and with 9 of them I can't keep track of which kitten has had which eye squirted. 

The day before he had any other flu symptoms one of the other boy kittens came home with one eye swollen shut. He'd been fine a few hours earlier and was covered in leaves and grass seeds when he got back. I thought he'd been climbing trees and scratched his eye. I put some drops in for him but it was swollen shut for two days and now the third eyelid is showing and looks very red and sore. I use the ointment and eye drops on him a few times a day but it isn't getting any better. Could this be an ulcer? His other eye is fine, not watering at all, although he has been sneezing since Tuesday. The vet gave me antibiotic tablets to use if any of the others started drooling. Should I start giving him these?

Are they better off inside or out? The room is kept warm and I have the humidifier on full. I noticed that some of the adult stray cats who stay outdoors all the time got over their 'flu in a couple of days. Is very dry air better for them? We're right up in the mountains here, it's dry and sunny during the day and drops down to around 3C or 4C at night.

My other cats have all been vaccinated but they've got flu symptoms as well. Not as bad as the kittens but they have runny noses and are sneezing a lot. Do they need a booster shot? Should I wait until they get over this before I get the booster or can they have it now?

Sorry about all the questions. My vet is closed until Monday afternoon and I'm worried one of them will go blind if I'm not careful.

Thanks for any advice.

To give them meds, try wrapping them up in a towel like a burrito.  They are definitely better indoors than out.  While you have them, you can work on socializing them and getting them used to human contact.

Thanks for the tip. I've managed to get the eye drops in by wrapping them in a towel like you suggested and then practically sitting on them while my husband squirted. 7 of them are pretty tame already but the other 2  can't be handled at all. Hopefully if they are eating and drinking they'll get better on their own? They don't look TOO bad, just snotty rather than infected.

I've been looking at pictures of eye ulcers and I don't think that's what Button has. The actual eye is clear, just the third eye lid is about a quarter of they way out and is red and the bottom rim is red too. I keep smearing eye ointment on to it whenever he lets his guard down. At least he is eating, got a better appetite than any of the others.

What do you think about booster shots for the other cats? Should I wait until the sniffles have dried up?