Technical question regarding major Forks

Can a fork on a chain, such as the ethereum now classic, also with bitcoin gold and bitcoin cash...I always read before it's released that it gets tested on a separate virtual platform to make sure everything works ok.
Ok, I don't like this idea of this many forks done, I guess once in a while it ok, but my real questions, what if something didn't go as planned...lets say the fork jammed after we thought it would work ok, does it leave the original Bitcoin intact?? Is there any way for them to actually modifiy the current state of the bitcoins as we know it.? This question would be similar to Ethereum since they also have their fair share of forks.

Also I don't like the idea of too many bitcoin gold, bitcoin cash...blah blah...is there a plan to this from the dev team? Whoever they are...unless there's a plan to attact more bitcoin users, it seems this can hurt or devalue it's image. or am I missing the point completely?

Once a coin forks off of Bitcoin, it has its own blockchain and thus cannot affect/modify Bitcoin's blockchain. However, the caveat to that is that if the new forked coin does not have a replay protection mechanism in place, any transactions made on either blockchain, can be reflected on the other one. Meaning that if you send the new forked coin somewhere, your Bitcoin may automatically get sent to a non-valid address or an address you do not control, essentially losing them. The same applies vice versa.

This is why many exchanges and wallets have announced that they will not be adding support for Bitcoin Gold unless they implement replay protection, which they are currently trying to do, albeit laughably.

As for people choosing to fork, that is not up to the devs. It is an open source project and literally anyone can choose to fork from Bitcoin if they so desire. But without proper devs, the chances of a forked coin surviving or gaining any traction are zero.