Yes, Delta Executor is risk-free. It is one of the most widely used and secure Roblox executors accessible. For desktop version you might use JJSploit or similar script executors.
Really, no. There aren't any Roblox exploits available right now that work with any of the scripts. Nevertheless, thanks to its unique module and UNC Support, Delta is able to support almost 99% of all scripts.
Depending on how you intend it. Roblox exploits are undoubtedly entirely legal, however as was previously mentioned, Roblox has the ability to ban your account, even though they haven't done so since late 2020. Absolutely safe, same as FPS Unlocker.
Make sure you're using the Roblox browser extension and not the Microsoft store one (roblox.com). Check out these instructions on this pastebin if it still doesn't work.