Summer of delays, cancellations and lost items - What are my options

Stalemate1123

In July and August, I had to endure a number of issues relating to air travel and now I'm looking at options on the best way to reclaim some of the costs, if possible. Any advice would be appreciated. This is an exercise of finding options I may have missed rather than looking to pursue airlines for something they are not responsible for.

1. Lost baby seat

Forgot our baby seat (£80) at Stansted airport while travelling to the south of Spain. I had to rent a new car seat (45 euros) in Spain and buy a new car seat (£205) after coming back to UK. I already checked with travel insurance and they'll only cover the cost of the original baby seat. 

Is there any other trick I'm missing in reclaiming any of other costs? 

2. Flight delayed by two hours resulting in missed hotel

Flight from Prague to Milan was delayed by 2 hours resulting in us landing at 12:30pm instead of the planned 10:30pm. This resulted in 1) missing our bus connection (30 euros) from MXP and needing to buy new tickets (30 euros), and 2) missing our hotel for the night (£100) as it didn't have a 24 hour reception and had agreed to extend reception staff only till 1am for us. We had to book a new hotel (110 euros). 

I think I can't claim under EU261 rules and travel insurance only covers costs if delay is more than 4 hours.

3. Non-UK/EU Flight delayed by 7 hours

Porter Airways Flight from Toronto to Ottawa delayed by 7 hours. Canada has a flight delay compensation system similar to EU. I have claimed on the airlines flight but is there a tool like Resolver which can be used for Canada to help expedite the claim?

4. Flight cancelled due to UK ATC issues

Flight from Athens to London was cancelled due to ATC issues last week. British Airways arranged accommodation, airport to hotel transport, meals and put me on a flight back the next day. Only thing not arranged was hotel to airport transport in Greece. I was advised that I can claim it back from BA but I can't find an online link to submit the claim apart from an address to physically post a letter. Is there an online link I can use?

Thank you. 

Caz3121

1. I would have thought the rental should be covered by the airline and, assuming the airline has classed the item as 'lost' (over 21/28 days) then claim for replacement
2. Nothing from airline for under 3 hours delay
3. Not aware but the airline website may have details of arbitration
4. should be an option through here https://www.britishairways.com/travel/customerportal/public/en_gb#/customer-service-portal