Very new to the community, I have worked with electronics and electrical for a long time professionally. But I am fairly new to the IoT movement.
I would try to stay clear from 5V as stated above, Power causes an inversely proportional relationship to Current and V, so a 200Watt load will be 5V and 40Amp, but a 12V would be 17Amp, 24V would be 8Amp, 120V would be 1.7Amps. Copper wire has a inverse relationship with resistance, so the thicker the wire, less resistance. So Amps of the load really drive the wire size, smaller wires with high amp can get to hot can cause melting, fires, etc, etc. Google American Wire Gauge size charts. AC vs DC does change based on length of wire.
But in this application amps are amps. So you really need to use 8awg wiring for a 5V, which is huge, and expensive. Going to a 12v system will decrease that a lot and you could get away with 12-14awg wiring, 24V even better. But 120 AC at this wattage is 18awg to the power supply. If you are stuck with the 5V system, you are better off going with individual PSs for each series, or run an individual wire to each series.
The advantage of 5V vs 12V or 24V LEDs is based on the application. 5V systems are more efficient, and you can get a lot more of them in a smaller area, which means they are better for screens and such. But if you look at outdoor screens for like a Billboard or TV, they take massive amounts of wattage, so they have huge power supplies and try to break up the series as much as possible.
Powering LED in series is usually never an issue, unless a strip is getting hot from another source. LEDs will absorb energy and either increase current consumption, or also back flow current when turned off if there is no Diode protection. Most Power supplies already have this backflow. But if your amps are at the limit, and one area gets hotter, you will see dimming in other locations.
Powering with one larger PS is best case if you can go with a 12v, or 24v LED. You can either control the whole thing with a SSR or SPDT Relay, or they have off the shelf IoT relay outlets. http://www.digital-loggers.com/iot.html.
If you want zones, you can get smaller relays for each series, they make -5v, or 12v relay boards, I have seen them up to 16 on one board. In this case a mechanical relay is fine, they have the risk of staying closed on failure(which is not a safety concern really), or you can go with SSR boards. Solid State Relays are faster, last longer, and 99% of time fail Open, but I have one instance. You can set these relays up with WiFi control, but need power supplies or you can use the 12v power. Or you can go with RJ45 jacks.
For color phases like RGB, you would need a single relay for each color. I think there are 4 circuit, so a 4 line relay board would be fine.
For wire prep, I do not like using bare stranded wire in a terminal. I would suggest tinning it with solder, or using a wire ferrule tool like http://smile.amazon.com/Signstek-Adjusting-Ratcheting-Crimping-AWG23-10/dp/B00HPRYIL8/ref=pd_bxgy_60_img_2?ie=UTF8&refRID=1467TGCH8NSRGMDG0X0E I would get the assortment of ferrules at 1st, then buy them based on what you need. They make jacketed speaker wire that is designed to go behind walls, this is the safest to use for DC applications. I would not use these for 120V AC lines though, just DC.
You can either go with a jack for each line, or you can use a terminal block. I like using something like this, you can cut them into 2 or 4 line terminals, be cautious of amps. http://smile.amazon.com/X3-0512-Position-Plastic-Screw-Terminal/dp/B00TX2Z2YU/ref=pd_sim_23_3?ie=UTF8&dpID=41bcH59ordL&dpSrc=sims&preST=AC_UL160_SR160%2C160&refRID=1Y2EM1Y5MYV2Y0809EEK
I prefer the solid backing LEDs over the flexible strips.
Sorry if that is too much info, or does not make much sense.