Can't seem to hit my long irons or fairway woods.

Play Russian roulette with your irons.  Lay them all down so that you can not see the club number.  Pick a random club on the range and hit it with out looking at the number.  Chances are the longer iron thing is all in your head.  All your irons should play relatively the same.

As for chunking, chances are you are decelerating on impact, try to take a shorter backswing and work on accelerating through the ball.

Your woods might be an alignment issue.  Play your woods off your front foot and keep your weight back through impact.

could be a number of different things...but if your consistently chunking and hooking shots it sounds like your swing plane and angle of attack are overly steep and you may be early extending to make room. If timed wrong the 'steepness' can cause you to chunk or your body instinctively knows and you stand up and flip your hands. Could also be too much lateral sway with upper body, but impossible to tell w/o video.

Generally speaking it's harder to hit driver/long clubs straight because the loft on the club makes the ball's curve more extreme when the path and face aren't lined up. ( D-Plane) Even slight differences between face/path with low lofted clubs cause extreme curve where not as much with higher lofted clubs.

I agree with trackster, if someone handed you an unmarked 4i, told you it was a 7i and told had you hit it you'd probably do just fine.