That wasn't noob at all.
1. According to Cathar a pump should use 50watts or less or the pump will actually be adding heat to the system.
2. Actual flow rates through most WCing systems using the Cascade/WW/RBX/TDX generally max out around 1.75 to 3 gallons a minute or 105-300 gallons/hour. This can also drop depending on how restrictive a loop is as well as how many components are in the loop. This is one reason the MCW650 is such a good WCing pump despite having a low overall flow rating- its maximum flow rating is right about the maximum flow one can expect through a standard WCing loop. These limits can be pushed BUT only by very special pumps like the Iwaki with the 27' head....yep...its a beast and its flow rate is still only 180gph.
3. Anytime the pump is put under strain (700gph capable pump pushing 200gph for example) it will generate more heat. In short getting too much pump that is too restricted will actually cause the pump to run hotter than normal
1)The pump is 60w (I believe - I'm almost 100% on it though) so I'm not too worried about the extra 10w.
2) This is fairly true. Most jet-style blocks eventually max out at flow rates of about 3gpm, my target rate for the WW. Although the 12v pumps are more efficient in design, one still wouldn't get my target flow rate and still have a good pressure. I'm not saying a high flow rate doesn't scale with high pressure, mearly a more powerful pump can pump the same amount of water at a greater pressure. Also, I would have gotten an Iwaki if I could affod/fit one. 125-150 for a pump is too much for this application. Plus, I will have to run a decent amount of tubing for my external box, probably around the range of 5-7' for a single rad/pump/wb loop. A single pass core laying length wise parallel to the case chews up a lot of space.
3) Also true. However remember that not all the heat generated by the pump is dumped into the water. This only happens with submersion pumps. I'm not sure of the exact figure but of the 60 'stock' watts the pump puts out, I'm willing to wager around 25-30 are put into the water. With the restriction maybe 40w? Also keep in mind that as the speed of the liquid increases, heat transfer capabilities (sp?) increase in the block and in the rad. at 3gpm, much more than the standard wc loop which usualy has ~1gpm, a radiator will be more efficient. Now factor in the fact that I am using a 2-342 to cool the loop and you'll see why I'm not worried about the added heat. AND having a fan blow over the pump should it get really hot will help a little too...
Basicly you have to figure when designing a loop is what are you looking for to maxamize what you have. You have to design around the 'target block' (most important block) first. My block excells with pressure + flow. Next concider what other blocks are in your loop and how they are going to effect the pressure/flow required for the 'target block' and what you need to compensate for that. Next you factor in the cooling capacity of your chosen radiator(s).
What I'm trying to say is you have to when the costs with the requirements to get the ideal setup. Sure, the mag 7 is probably overkill. A mag three probably would have worked fine but I feel I'll be able to run it fine and with the extra power it provides, show a noticable difference with it compaired to other pumps. We will see though.
Oh, and I have a second loop. It's a maze4gpu, zchip, jr-120, and Hydor L30I. The flow through it is approximately 1.5gpm, well balanced I feel concidering the zchip is a flow killer.