Unless you intend on racing the boat, I wouldn't glue it together. If it's excessively loose, use shims cut from beer cans or vinyl siding to take the slop out.

If your intent is to sell it after a year or so, I'd concentrate on the cosmetics - do a flawless paint job (all the work is in surface prep), replace lines (cheap) and clean up the tramp (new hiking straps?). New sidebar carpet, too. You can buy black carpet runner from Home Depot for about $15 that will do two boats' worth.

If it's got black anodized aluminum, you can use silicone spray to make it shine again. Just spray it on, wipe off the excess, wait a few minutes and wipe it down again. It works wonders.