Please check the following.

Could you please check if the following are correct?

What's the latest you have ever hadone your lunch?

The latest I have ever had my lunch is two hours. (Context: I eat my lunch at 2:00 p.m. and some days I'm late and have it at 2:30 or 3:00. But, today I took my lunch at 4 and it was the latest)

When is it you have ever had your lunch the latest? Or, is it 'When have you ever had your lunch the earliest'?

It's today./ The latest I have ever had my lunch is today. (context same as above )

I have got a same question regarding 'earliest'.

What's the earliest you have ever had your lunch?

The earliest I've ever had my lunch is two hours ( I usually take lunch at 3, some days at 2:30 or 2:00. But, today I had it at 1:00- the earliest lunch ever!)

When is it you have ever had your lunch the earliest?/ when have you ever had your lunch the earliest?

The earliest I have ever had my lunch is today.

And also, could you please tell if the following case should be a singular or plural?

There is/ are infinite number/ numbers of possibilities around us.

My problem is actually with 'infinite'.

Please help!!