i) What will be the largest external USB Hard drive supported?
Skippa can read from and write to an 8TB HDD in a USB caddy okay.
ii) File system? (FAT 32?)
Skippa can read from and write to FAT, FAT32, NTFS and EXT4 (I didn't try EXT2 or EXT3). Skippa can NOT see exFAT formatted partitions/drives.
iii) Will the external HDD need to be divided into multiple partitions, and what will be the max partition size?
Multiple partitions are not necessary, but Skippa can read from and write to drives with multiple partitions.
Skippa will always move recordings to the 1st partition of the 1st drive, or the 1st drive if the're only 1 partition. You don't get to choose the destination drive or partition to move recordings to. You also don't get to choose the folder. Skippa creates a top-level folder named 'skippa' and moves the recordings there.
The device info menu page can only fit the first 3 USB drives in the displayed list of connected USB devices. But the actual media menu where you access Local Devices (i.e. USB) or Network Devices (i.e. DLNA) can list many more. I had a USB hub with 3 USB sticks and a USB caddy with a 2 partition USB drive connected and it listed all 5 drives/partitions.
iv) To search through a listing of all the content on the external HDD, will the user have to manually switch from one partition to another?
Yes.
v) Will any functionality be lost if content is stored on the external USB HDD rather than the internal 1 GB HDD? (e.g. will ad skipping still work? full program meta data still retained?)
Currently, yes, meta data, resume points, bookmarks and auto skip points are not moved to the USB drive with the recording. These extra files (or at least 2 of them) are moved with the recording to the USB drive but they are 0 bytes. I believe this will be changed in a future firmware update but I need to confirm this.
vi) Same questions, but applied to content moved from the Skippa internal HDD to external network storage or media PC. Will exported via WiFi be feasible?
Recording can only be moved to an external USB drive and not copied, so answer above applies.
There is no LAN or WiFi access to or from a computer, other than streaming to a DLNA media player or from a DLNA media server. Skippa is both a DLNA media client and media server.
You can copy a recording's DLNA url from a media player (like Windows Media Player) on a computer and then paste that url into the address bar of any web browser to download the recording's TS file directly to a computer. The TS file will have a number for it's filename so you will probably want to rename the file after it downloads. You can copy the original show's name from the properties in the DLNA media player (where you get the url from). No meat data is copied with the recording when using this trick.