This thread actually has potential if anyone cares to get it back on track.
I don't like ANY of the mods, sorry freak. Number one has potential, but it's not really a 5-min mod. It's a cheesy method to stealth anyway.
Number two will show no benfits to cooling, but will for sure catch you one day/night while you're borking around the PC sometime. One slip, and you'll get the infamous "pthhllllll" of your fingers getting flipped by a fan or two. I still get knuckle rub digging inside, and I'm very glad the waffle-mesh is there. All you really need on a fan's intake side is volume. no straight shot, nothing...just volume; and it gets it with the grill on or off. With the way fans are build and designed, you'll notice that air only moves around the areas of the blade tips on outward anyway. There's a big deadspot about 2" wide in the center on typical 80mm fans.
If you want to improve airflow of the fans, then it's going to take some type of ducting. I'm not big on those large tubes, but find that even a 1" long extension straightens out the pinwheel of air and regroups it so it's just not flung into the case. You'll have to be creative here, but it could be done.
The third one is the most scary. Just taking a piece of sandpaper to the bottom of a HS is a very horrible idea; polish or not. When you take a piece of sandpaper into your hand and start sanding, your fingers are the pressure. Your fingers are not at all even, and you will be sanding highs and lows into a flat surface. The bottom of a HS must be perfectly flat...hense, "Lapping". Lapping is taking a known flat surface (or in circular objects such as valves in your vehicles heads; a known round surface face) and using it as the standard. I like glass for lapping. I have a starrett marble top standard at work, but have found that a piece of glass works just as good. You lay your media (that's "sandpaper") and lay it on the glass, then you move the HS on the media. It's important to move the HS parallel to the surface, or you'll be sanding the base at an angle. That'll make the HS sit lop sided, and the mounting method may or may not work then. Either way, it's not really good.
Polishing may have it's benifits, but theoritically I've doubted it for a while. A perfecly shiney polish job will remove all the micro-grooves out of the contact surface. Now, in theory, you want to cram as much surface area into that small contact area as possible. Not gouges, but some evenly done micro grooves left behing from a machine or your media can't be all that bad IMO. If you look at a swiftech(I think) HS, you'll see that the pins on it have grooves kinda like screwbolts...this is additional surface area. Also, extensive engineering on the IHS on both Intel and AMD procs has found that the surface they ship with is the perfect medium for heat transfer, and it ain't shiney. Either way, the way they come from the retailer is important, but I wouldn't go further than lapping the base and skip any polishing steps.
I'll try and come up with some 5 minute mods and pop back in. My 5-min mods turn into all nighters, so I'll try and condense them to what a normal person may do...