1. There is a solution for small transactions. Its the second layer on top of the Bitcoin network known as the lightning network. It is still being developed and implemented but it is making significant progress and the network is growing rapidly. Small (micro) transactions will not be an issue on this second layer.
2. It isn't easy to just switch to PoS. Proof of stake simply does not provide the same immutability and security as Bitcoin. Plus some argue that Proof of stake will lead to more centralization over proof of work. It simply just gives the power back to the wealthy elite. The more money you have, the more stake you have in the network. Same as the traditional fiat system. Also, a transition to PoS could also potentially be very risky for a network as large as Bitcoins. PoW is still the best consensus algorithm in terms of security and immutability, which is highly important..
1. Thank you for your input, the LN couldn't come any sooner! xD I know they are working hard to release it as a final version but damn when you need the money to make a deal and it's just not there when needed it really does cause some problem.
Yeah, It can definitely be frustrating if a transaction is taking too long. If that happens again, try checking out a transaction accelerator. Some companies offer services to speed up your transactions and sometimes it really helps out!
2. The same can be said about PoW. The more machines you have mining the higher your chances are of gaining coins. Yes you can join mining pools but the same is still required. The more input you have working for the network the higher your chances are of gaining coins. These 1060's to 1080 ti's are not cheap by any standards and I've seen the price increase by £200 over the past year and a half or two because of high demand and low supply.
Well, with PoW there aren't that many mining machines out there. The wealthy elite wouldn't be able to buy that much mining hardware because there just isn't enough supply. Mining hardware quickly becomes obsolete as well, so even as more companies produce miners, the wealthy elite wouldn't be able to buy enough as the supply is low, and the demand would further drive up the costs of the miners. Whatever hardware they were able to buy would be outdated once difficulty increases. Immutability and security are paramount for the network as well, which is why PoW is one of, if not the best consensus algorithms out there.