Of course, absolutely true, as I said above. I could also construct a family of reasons for each of these. More and more elaborate explanations, increasingly detailed and complicated and byzantine. Rube Goldbergian mechanisms. However, science has other requirements as well, such as:
Parsimony
predictive success
And of course, most of those alternative explanations will fail those and other requirements. 
It certainly can be amusing to try to construct alternative theories to explain this evidence. And amusing to try to come up with more evidence. It is all good mental exercise I would commend to anyone. How many scientific facts/observations/pieces of evidence can one come up with to "prove" the earth is round ? (I use prove loosely here, since there is no proof in science only in mathematics and logic). 

One caution I have, is that some of these explanations are clever. Some are just silly, like saying the earth is not warmer now than it was 100 years ago. However, the measurements are the measurements. And even when all kinds of corrections are taken acount of, the temperatures now are warmer than they were 100 years ago. Done using thousands of instruments of different types in different locations by different people who got consistent results. Incorrect theories are bad enough, but bad data is fatal. 

As to your other questions, it is easy to measure the earth's free oscillations with a weight on a spring. It is done all the time and has been done for decades. And they have very characteristic temporal and spatial frequencies corresponding to oscillations of a rotating sphere. A bit hard to wave your hands to make those observations go away. You might be able to do it if you were really an excellent applied mathematician and willing to spend a few months in crazy speculative inverse theory computations. Currents of course are possible, but these are very special kinds of currents that have special kinds of characteristics that match what one would expect from a fluid on a rotating spherical earth. I have personally seen the curve of the earth when standing on a very high point. Now of course it could be an optical illusion, but it is a very compelling one if it is. However you can put it down to refraction or some other optical effect. In fact, you could even put photographs of the earth from space down to those. As I said above (and you nicely demonstrated my point), you can explain almost ANYTHING away and maintain some pre-conceived notion if you are willing to throw away parsimony and the demands of prediction, etc.