Why not add some HDMI switch or matrix for the last few items? More than 4 HDMI devices is not unheard of and you can put the last few things that don't need ARC there.
I've got a Sony STR-DN1040 and a Samsung UN55JS8500 with one-connect mini. I currently have it set up such that all of my external devices (Nvidia shield, wii u, xbox) are connected to the one-connect mini hub (ie the TV) and there is a single connection (output) to the Amp via the one ARC compliant port. this allows me to use my harmony remote / switcher capabilities of the TV and maintain an audio connection to my speaker set up via the amp. However, the one-connect mini is limited to just the four hdmi ports (cable/SAT, PCI/DVI, 3, and 4 ARC), and i have a new device i'd like to connect. The amp has plenty of hdmi inputs and a built in switcher, but when i try to put all inputs through the amp and have a single essentially video out connection to the samsung TV, it is constantly fighting over the HDMI control protocol and changes the audio / visual input so that it does not work properly. Samsung has said there is no option to purchase a one connect with more ports, and essentially told me there was nothing i could do, which seems silly. Any help is much appreciated. Perhaps, I connect the amp via optical audio instead of hdmi, and truly use it as an audio out only? and use 4 as the new input?