I don't believe 300.3(B)(3) would include the words cable and cords if it only applied to individual conductors. NM and plastic boxes would comply with 300.20(B) because it says where, and since we don't have any "where" single conductors pass through ferrous metals, we are by default already in compliance.

Since the tree was probably a landscape planting, there are lots of options. The Pinus key on the FNA site show Pines that are native, or have escaped, and these Pinus maps at BONAP provide distributions for those species in the wild. Those two resources show that Pinus echinata has straight needles of that length, and is also comfortable in northern climates. However, an accurate ID isn't really feasible from the information provided. You might take your photo to local nurseries, to see if they can tell you which Pinus species are typically selected for local plantings.

3/4" usually looks more contemporary/Euro. That looks like a freestanding range, which should have some leg height adjustment, you should be fine...

Your situation really doesn't surprise me, if I have seen it once I have seen it a thousand times. While the bedroom / bonus room have low air as you stated the combination of this problem plus no return or thermostat control in those areas just due to where the equipment is placed or the longer run of those ducts can create comfort issues in the heat of summer. When there is light exposed to what the real problem is gives a better ability to offer things that will rectify the issue. In dealing with hot spots a zone system is a higher cost option to rectify the issue for the simple reason a zone system has the ability to better control a system. The caveat if you will is the 'design'... the other thing is architectural limitations of the structure. While some situations in which a zone system is used can reduce equipment costs, that is not it's only function. If rooms are a considerable difference from the equipment that serves it, a zoned system may be the best method to rectify that issue. The other method would be to relocate the equipment to a more central location within the structure so that the ducting to each area is more equal. In a zone system the equipment will cool / heat each zone independently so while location of the equipment is still some what important, not as much as a non-zoned system. A new return added to a hot spot will help, but it may not rectify the issue 100% for the simple reason the thermostat location now can not sense temperature in that area. If you move the thermostat then the problem is merely shifted to a new area outside the reach of the thermostat. This is how a zone system excels. Provided the design is done correctly. While it's true that 2 speed, 5 speed and full on inverter systems excel in a humid climate, that is not the only purpose of those machines. Because of the high utility cost in the location of where this structure is... it is in the interest of this home owner to choose the most efficient equipment they can. If it were me I would go with Inverter system 20 SEER or higher. (5 speed or full inverter variable) If you can't afford both at once or you want to make sure a company is worth their salt, consider awarding a company with the system that has the problem area first. Tell them if they rectify the issue with the trouble spots you will reward them with replacing the other system as well. If you hire them and it goes terribly wrong, hire in another contractor to fix the problems and then you have something to use leverage to get another contractor to take over the maintenance and service of both systems... the contractor who fixes the problem system gets the right to replace the other system. Additionally given the information of those hot spot problems, trying to drop this to total of 5 tons of cooling would be a disaster. For others that happen to read this thread with similar problems I service the Katy, Texas area.