HTupolev

Keep in mind that "low 20s" refers to showroom weight, which sometimes doesn't even include pedals. If you're planning on using full-length fenders and rack(s), plus pedals and bottle cages and spares, a 23lb entry-level gravel bike is going to be a heck of a lot more than 23lbs. My '79 Fuji America sport tourer is 24lbs according to the catalog, but as pictured here it weighs about 31lbs (blue bike in front):



So while your bike is definitely no lightweight, depending on how you're measuring it, it might not be quite as much of a brick as you think. If it's 35lbs as pictured, you're nowhere near Varsity territory.

That depends mostly on you. Actually, for reasonably hard-packed trail surfaces and most gravel you probably don't even need to change anything from how it's set up right now. Why not just give it a go and see what you think about it?