So you can absolutely overkill on filtration. I did it and learned my lesson the hard way. I was running a carbon reactor, gfo reactor, bio pellets and a skimmer. I ended up stripping my tank and getting the dreaded dinos.
You need to have a good bio load going in and also coming out. Get a skimmer rated for the bio load you have is IMO step one. In my 60 cube I have 8 fish. Some are fairly large. I also feed fairly regularly. So I got a skimmer that had a high bioload of 60 gallons. I also run light carbon and light gfo. I test nitrates and phosphates weekly to ensure I’m at my target to not strip the tank and to not have algae problems.
Tank listed is a great tank. And some of the equipment is great and some is not so good. I’d recommend getting some other items in replace of some. Such as the API test kits. Those really aren’t that good. There’s a tons of wonderful brands on bulkreefsupply.com.
The protein skimmer they are showing is a Bubble Mangus. I had one of their curve 5 and wasn’t a fan. Single point of adjustment and all it did was over fill no matter what I did. I’d recommend maybe a Reef Octopus SSS110 or nyos 120 over that any day.
It is always possible, but from the link you are referencing, it shouldn't be a problem adapting all of the equipment for a 70 gallon setup to a 60 gallon setup. Just as long as everything fits.
Agreed with the above - you can actually strip your system of nutrients, which is why I run as little 'add on' filtration as possible.
Now, if the question is if you can overkill on biological filtration, like bio bricks or matrix or something, I'd say the answer is no unless you have so much you're literally blocking water flow.