Toddler travel--products and advice

I recommend an airline-approved car seat vs the footrest/bed idea due to my experiences: 1. Kiddo was used to and felt comfortable in her car seat. She was happy to be buckled in as usual. (When we once made a short flight without the car seat she kept unclipping the seat belt and seemed to feel uneasy.) 2. My kid always slept best during the last hour of the flight. I could tidy up and organize our possessions while kiddo slept. With the carry-on bed I imagine you must pack and store it for takeoff and landing. And when there is turbulence the car seat seems more practical.
My best “toy” was a dispenser of scotch tape. I’d file out 12” at a time and let her ball it up etc. Great fun. Have a great trip!

Not to rain on your parade but have you confirmed with the airline that they will allow the airplane bed? My kids are too big for them now but I have heard that some folks have gotten it all set up only to be told by the flight attendants that they cannot use it, even in a window seat. 

If space and funds allow, I might instead suggest that you consider buying an extra seat. The last time I took my older kid to Europe, we bought an extra seat in our row of 3 so the middle seat was open. You do not have to pay taxes or fees on the extra seat since no one is sitting in it so it is literally just the cost of the ticket. For us, it was $95rt for a $400 rt/ticket. It made a huge difference in comfort level but with the extra seat you cannot online check in so we had to allow for a bit more time at the airport.

My 2 kids use these headphones: https://smile.amazon.com/gp/product/B07PD9V78L/ref=ppx_yo_dt_b_asin_tit…

I think they're sturdy and have held up well. They were $19 but are currently $11.50 on Amazon, so that's nice. My youngest used them at 3 years old - I think they'd fit a 2.5 year old head.

As for non-screen airplane activites/distractions... these "Boogie Boards" are fun: https://smile.amazon.com/gp/product/B010HWCEFY/ref=ppx_yo_dt_b_search_a… They're like LCD writing tablets, you use a stylus and draw/write on it and then push the button and it erases and you start again! 

Or what about a small set of Picasso Tiles? (like Magnatiles but without the brand name sticker price, and just as sturdy/great). I think they'd be fun on the tray table, and my boys can have fun with even just a small stack of different shapes  https://smile.amazon.com/PicassoTiles-Construction-Educational-Engineer…

We are also no-screen, and our son did his SFO to Europe flight around 3.5 years old a couple of years ago.

Headphones:

I'm assuming you're asking because you want to protect your child's hearing, not so much just for music. I bought my son kid-sized noise-cancelling headphones from Amazon for about $100. Total waste of money! It was static-y and the noise cancelling wasn't enough to dampen the plane noises, the band kept sliding off of his head, and were too tight and smooshed his ears. You shouldn't expect there to be high quality anything for kids in this area, because kids break things. My partner had ~$350 Bose headphones, I had $300 SONY headphones, and we also had a pair of $20 safety/noise dampening ear muffs (we got it for watching car races up in Sonoma). Each fits a little differently, had different tension around the head/ears, and we let him switch between the three all through out the flight to be more comfortable.

We didn't have a sleeping bed, but his was a to sleep for a few hours here and there with his head on my lap.

To make it without screens for 10+ hours (besides turning off the screen in front of our seats):

It was a tag team effort between the parents and required cycling through different activities.

NEW TOYS. We gave him one when we got on the plane, and told him there's one more when we land, if he cooperated with us. I don't remember what the new toy was, I think it was a paw patrol figure (we don't watch but he found out about them through preschool, so this was a high value item). Overall, this occupied him for almost an hour.

BOOKS. We had new books and we'd bring out one at a time to read with him. The 5-minute stories books worked well for us, and a few cars books. We also flipped through all of the magazines in the seat pocket. Those were extremely interesting for him because we don't have magazines at home. Reading was probably a couple of hours. This flight didn't have duty-free inflight shopping. If it had, I would've let him pick out something to buy for being a good boy.

SNACKS. I had several kinds of snacks with me, and I let him open the packages to kill time, lol. Another hour.

AIRPLANE FOOD. I pre-ordered the vegan meal for myself, the kid meal for him, and my partner chose one of the standard options that got wheeled around. My plan was to have three totally different meals so he can pick what he liked and maybe even try some new things. I'm not vegan, but I knew the vegan option would have fruit and probably carb-y things that my son would like. Letting him eat as slowly as possible also was a good time waster. Another hour.

Looking out the window. We would talk at great length about what we see and if there's anything interesting down below us. Another hour.

Listened to music. We let him listen to whatever music he wanted from headphones plugged into one of our iphones and relaxed with his blanket. Another hour or so.

He slept for about 3-4 hours total in a couple of chunks. It's doable, but a lot of work, and once we landed everyone was exhausted.

Lastly - one thing that I would do differently is that I would opt out of priority boarding. Sitting in our cramped seats waiting an extra 45 minutes for everyone else to board was brutal. It would've better to board a bit later and get to walk around the airport longer.