Traveling with a baby and a kid

I am traveling alot. My family travels alot. We fly at least 4 times per year globally, to cover family visiting and vacations. At least once a year, we all fly to Korea, to visit my family. It makes me somewhat an expert on flying with small kids. Yet it is always rather struggle to get some valuable information regarding traveling with small kids. Now I want to share my hard learn knowledge with other poor souls.

1. Flying long distance: seat and bassinet

Check with the airline regarding bassinet policy. I have been using Lufthansa for last 3-4 years. I liked it, since it has nice and spacious airbus 340 with many and roomy toilet area, and a big bassinet ( about 75 cm x 37.5 x20 ( guessing, not exact size of LH) and I think it was up to 15 kg, or so. They never fussed over weight or size of a baby as long as the baby is under 2 years. It was very easy to get a bulk head seat with friendly service. They also seemed to have more bassinet seats available compare to KLM, and 2 seats row was working nicely with me + a 3 year old + 6 month baby.
Now, I wanted to try something different and booked KLM without checking first. To my horror, they have a smaller bassinet only for up to 9 months baby who is max. 65 cm, 9 kg! Even if the baby is small (size of 63cm and 8 kg) and fit for the size of the bassinet (71cmx30cmx20cm), the age is matter (14 months), and I was flat refused! Because the baby might be bigger a month later when she is flying, the service said. I think it is disgraceful. They also have only 4 places for such bassinet. If I knew of this, I would have definitely not buying KLM. Certainly I do not recommend it to others. They would not give me any bulk head seat at all, since the service line do not have access for those seats. I was told to go to the airport early to see if it is available, yeah right!
After a week of struggling with KLM service, I finally extracted a critical information accidentally: that if I bring my own basket, they can request for a bulkhead seat. I will find out, if I get it after 48 hours. I am not impressed with whole thing so far, and just pray the 10 hour flight is not going to be a hell. I am seriously considering, that buying a seat for the little one. The child seat is supposed to cost 75% of adult price. However,it is discounted from the fare only, not the taxes, so in reality it is rather 90% of the full price.
At least, KLM allows a car seat to be used, if you buy a seat for the baby. But the seat is small (42.5 cm width) so one have to be sure of, if the car seat fits. It is expensive to buy a baby seat, but I do think it is much safer for the baby, if you can use a car seat. Some airlines do not allow a carseat, nor even provide a baby belt for take off and landing. LH provides it, but not SAS. I think I shall get my own baby belt to bring it with me in the future travels.
I plan to let my big one (almost 4 year, about 108 cm) to sleep on the floor in bulkhead seat, and have the baby on the seat. One could bring something to protect the child head and body from hard corners and seat-legs.

2. useful equipment for traveling with a baby and a kid

Now, I really wonder if I should start my own business for baby traveling. Just because it is so under developed market. Very few, but I found interesting stuff on the internet here. The sites are for demonstration purpose and quoted randomly, not for the best shop.
2-1. Samsonite baby travel cot : pop up and compact (bed: 88cm x 55cm, when folded: 27 cm). It even comes with sun shade and net. I wish I knew of this before. It is for babies. You can not buy this easily in Denmark. UK seems to have a better market for it.
2-2. Inflatable travel cot : looked very interesting. I do not know if it is good to use.
2-3.Kelty convertible stroller and backpack combi
: impossible to buy it in Europe, but it looked great. There are reviews that the stroller is not as smooth, but when you travel in Europe or places that are not stroller friendly, you can use the backpack. It can be used until 20 kg. I am considering to buy it (about 176 us$), though the shipping and tax might be more expensive to buy from US. Ah, the horrors of living in Denmark, with import tax.
2-4. LeapPad: This seems to be better than Videonow PVD player. I am waiting for mine to be delivered. This is for entertainment for my almost 4 year old in long distance travel.
2-5. disposable baby front cover for feeding time: In Denmark, you can buy this in Bilka, 10 in a package. Quite useful for small, drooling and messy babies on the run.
2-6. plastic cover for strollers for sun, rain and wind : you can buy it in Korea, cost about 17 us$. I have other brand, and it is one of must-have. If you have a Korean friend, ask them to order it for you.
2-7. Car seat and folding stroller in one ( under product, it is second item) or see here : about 500 us$. You can find similar thing in Denmark, I think. This is a good Korean design, and the set can incline backwards up to 175degree, and claims that can be used up till 5 years old, which I guess Korean child size. You can detach the car seat and use separately. I am going to look at it when I travel this March with KLM.

3. Things I wish I had

3-1. check-in size- rolling travel bag combined with a child stroller: I read about a US woman invented this product while ago. Good idea, and wish it exists.
3-2. Folding stroller for both a baby(seating or lying) and a kid (seating or standing) same time in one: it couldn't be that hard to design some thing like this, isn't it? or at least they should have something that the big child can stand on. In Denmark, they sell something called 'big sister stand', which is a panel with wheels, and you can attach it onto the baby trolley. Smart, but it is only for those big baby wagons and brand-specific.
3-3. small folding chair that fits in leg-room space in a airplane: I am thinking of making one myself. So kids can play and seat on it.
3-4. soft form bottomed sleeping bag for small kids, to use it in the air plane floor.