Yes you can use the appropriate flare unions to join lengths if it makes it easier. Compression fittings are illegal though. In a really difficult location doing so makes sense.

Sometimes I take heavy grease and a brush and coat brake lines. Otherwise in your harsh environment rust will get them.

Also when replacing one leaky and you get the hang of it. Inspect the others on the car and replace the ones that look really bad as well. hopefully none will.