That would just copy the firmware from the STM microcontroller.

It's already cancelled, at least on my end - it entered cancelled state after running grin wallet check.

Difficult UX is putting it lightly. I would consider myself quite a geek and it's confusing even for me, there is very little valid documentation on how to use it. I also seem to have permanently lost some GRIN from unintentionally cancelling a transaction (?!).

Monero will have a MW sidechain soon - I think it will be more promising than Grin, at least currently. I do like that Grin is implemented in Rust, but it has too many technical issues currently.

750Ti can mine Monero at a very low hashrate, but it is quite power efficient. Probably capable of some other algorithms too, although at low speeds.

If you want a new piece of hardware, just get a small x86 rackmount (with Atom or Celeron is okay) and use something like VyOS (https://vyos.io/) or PFSense (https://www.pfsense.org/) - it will be able to handle much more traffic than an 18xx ISR as well as many more features. Supermicro makes some good cheap barebones machines with Atom CPU in a quarter-depth 1U, about the same size as 18xx ISR.

It's normal, the GPU needs to be controlled so the CPU spends time doing other things. If there isn't enough CPU power to feed the GPU the GPU hashrate will drop too.

The oven trick hasn't worked since RoHS/leaded solder ban anyway. The new soldering compounds require much higher temperatures and won't reflow in a typical oven.

"CPU coins" (assuming you mean ASIC/GPU resistant coins) tend to require much more complicated logic and/or large amounts of external memory. This makes them fairly inefficient for FPGAs as well, so a DE10 nano (Cyclone V) is even less suitable for those algorithms than the 1525.

Those GPUs are too old to mine any coin effectively. Even with free power you would be earning less than $1 per month. Also, why are you switching to a Cisco 18xx ISR for a router? They're very underpowered (an 1841 can barely do 20Mbps NAT throughput without maxing CPU).

You need larger disks or more actual RAM then, it's unavoidable. You could just use large USB keys for the OS, to save money.

Use Linux. The mining process doesn't actually use any storage on the disk, Windows is just inane and requires disk to back virtual memory.

They intentionally targeted an ASIC friendly algorithm and want ASICs to join the network. Obelisk worked with Grin's team while implementing their prototypes, even though they weren't directly contracted.

Is the pool server listening on port 8545 ?

That depends on the pool you're using, not all pools support those features. They will usually have this information on the "getting started" pages.

If there's no option in your BIOS for it, not something you'll have to worry about most likely. I would also try to see if the cards show up in Linux (lspci) when they don't show up in the BIOS - the driver stack might reinitialize the cards if they did fail to POST. You can also rescan the PCIe bus or toggle which slots are enabled and see if they'll be detected.

Then elaborate on your original statement - why hasn't your miner hashed for the last two months? What do you mean "the correct pool" ? There is no one answer to that question, so we need some more information about what you're looking for.

If it isn't power delivery, make sure 64-bit PCIe BAR is enabled and mapping above 4GB aperture is allowed.

Go choose any coin that's lyra2rev2 compatible, and find pools that support that coin. Or, point it to Nicehash and sell the hashrate directly. It's your choice...

You can choose whatever pool you want. Maybe you should've done some research before buying it, if you don't understand what you're doing that's not the manufacturer's fault.

That depends on your dexterity, of course, but it took me approximately 30 minutes to disassemble an RR210 and repaste all the boards.

What do you mean "how long" ?