Well let's go over your points, one at a time. First you say that common descent has nothing to do with origins. Well, it does.
No. It doesn't. Definitionally, it doesn't. I really don't understand how you're not getting this.
Let's say that aliens wiped out life several times, and put new, but similar life forms on the earth, using them to kind of shape the world. It could be easy to be fooled into thinking that life evolved, when in reality it was scratched and re-created.
Okay. This has nothing to do with terrestrial abiogenesis (life arising from nonlife here on Earth) and has everything to do with
life arising multiple times independently. Do you see why those are independent? Why either one could happen without the other? Secondly, is this a falsifiable hypothesis that would result in evidence different from that of common descent?
Evidence for alien seeding of the Earth? how could you ever obtain that.
That is our point. You can't, so it is an unfalsifiable hypothesis. Unfalsifiable hypotheses could be true, but they are not scientific hypotheses because they cannot be disproved.
I suppose if it is true, they would return soon to remove Man because he is destroying this wonderful world.
You suppose? Okay. Are you willing to put a date on when this will occur? If it is within a human timescale (the next 30 years, say), we can call this hypothesis falsifiable! Of course, you'd have to justify how the alien species would be able to visit in the first place without having been detected yet (this would be a high-energy device coming straight towards us) and also how we could differentiate "regular" alien invaders from life-seeders.
With evidence already existing regarding Aliens, and before you say anything I realise there's a lot of fraud out there, but for every government in the world to classify something which doesn't exist seems odd.
This is not a sentence. I could try to parse it to figure out what you meant but I do not think it is worth it in this case.
With regards to dinosaurs being very quickly destroyed and fossilised in that state, there are far more than a snake. T-rex fighting a triceratops for example, or a Velociraptor eating its prey. If it was a blast from a meteor, well I can't imagine those scenes existing.
The mistake you are making is that you seem to believe that all fossils formed at the same time--directly after the meteor hit. In reality, almost
none of our fossils are from that point. That is not surprising, because (of course) the vast majority of the history of dinosaurs occurred before the meteor hit.
I'm not trying to enforce we were actually seeded by aliens, I'm giving it as a hypothesis that could be as strong as any other.
It is either an unscientific hypothesis, or an
incredibly weak scientific hypothesis that is not nearly as strong as many others.
It has the same evidence shown so far by abiogenesis which is virtually zero.
The "alien" hypothesis is also hypothesizing abiogenesis, just not terrestrial abiogenesis. It is also hypothesizing multiple visits from an intelligent alien life form, most likely in flagrant violation of the laws of physics, which for some reason decided to plant evidence to make it look like common descent was accurate. Even if we assume there was some sort of falsifiability about it, the "alien" hypothesis is
implausible to an absurd degree. Terrestrial abiogenesis is not.
I'm also trying to point out HOW a problem found in abiogenesis could show evolution as wrong.
You have not accomplished this, and you never will so long as you continue to be confused about (1) what makes a hypothesis falsifiable, and (2) what the theory of evolution through common descent actually states.