New 1x10 project advice?

The whole purpose of the front derailleur is to narrow the angle that the chain is moved across, between the front ring and whichever of the rear cogs that is chosen. It adjusts the chainline on-the-fly.

No. It simply forces the chain onto a different chainring when employed. After which it is not in contact with the chain. If when shifting along the rear cassette the front derailleur comes in contact with the chain, it needs 'triming' out of the way.

Also a 1x9 set-up on a MTB is often aided by a one sided 'chain catcher' and a bash guard. So for a road set-up the Paul guide above may be a better option. Although you are more likely to drop the chain on the inside. If it is a problem at all.