EA/Respawn does not own the servers?

That's typically how mostly all game developers do it. I've never really heard of a video game developer having their servers owned by them.

1. Can the tickrate be improved if they switched companies for their servers? Sure it could if they wanted to do that.

2. Can the servers actually be improved? This would lead back to the first question. With a different company they likely wouldn't have the exact same hardware, so they could have faster servers, which could allow them to increase tick-rate. They could also have better network security as well.

3. Should Multiplay be blamed for the recent server hacks? Yes, and no. Server providers provide the physical hardware and network infrastructure for video game developers, video game developers then upload their server software to the server to allow others to connect and play their games online. Remote access passwords etc is likely setup by Respawn. Multiplay however would be in control when it comes to server attacks such as DDosing and things of that nature. So as far as what seems to be DDosing in some occasions I would say the server providers security could be to blame. But the "savetitanfall" hack was Respawn's fault I believe, due to the hacker seeming to use the same method of accessing the servers that Respawn uses. The hacker probably just found their passwords somewhere and connected.