How will a 'gateway' restriction affect IPFS & Ethereum?

Since these are 'gateway' related restrictions there's no impact on the content hosted on IPFS or Ethereum. Instead, it will only make it impossible to access content through Cloudflare's service. It's not clear how many of these restrictions are abuse or copyright-related, as not much context is provided.

What is block time in Ethereum?

Block time refers to the time separating blocks. In Ethereum, time is divided up into twelve second units called 'slots'. In each slot a single validator is selected to propose a block. Assuming all validators are online and fully functional there will be a block in every slot, meaning the block time is 12s.

Is the timeframe for Ethereum Block finalization too long?

The Ethereum community has acknowledged that the current timeframe for blocks to be finalized is too long. “Having a delay between a block's proposal and finalization also creates an opportunity for short reorgs that an attacker could use to censor certain blocks or extract MEV ,” the Ethereum website shared in a blog.