I wouldn't even go into LTC at this point; there are more profitable scrypt coins out there (some more stable, some massively unstable).

Having free power, you're very lucky. Once you establish some trust, you can get  into both running your own miners (by purchasing ASICs and supporting equipment), and hosting miners for others (assuming you can troubleshoot, have a stable internet connection, etc). I'd definitely read over the requirements and manuals for equipment before ordering where possible, and practice dealing with crypto coins by mining some X11 coins on your computer directly.

You could also invest in cloud mining. I personally have used cex.io which currently gets you a gigahash/sec of power for just over BTC0.007 and lets you resell the power later. An alternative that I haven't used (and that is fairly new) is PBMining that sells you 1 GH/sec for 0.004, and keeps it running for 5 years. You can calculate your returns using a mining calculator. All you need to set is the hash rate field.

Currently,  the sound of FPGA fans, though not for mining at the moment.

Thanks, I'll have to look into that. The cloudmining services are fairly convenient compared to miners at home and ghash.io has been inching closer and closer to the magic mark...

At a lower level, miners are always trying to solve the problem of mining (SHA256(SHA256(coinbase+nonce))) and trying to minimize that value. However, they can send in solutions that aren't as good to the mining pool (called shares), and when someone does get a valid block, they send it to the pool, which then shares the profits with the miners based on how many shares they sent in, less any fees.

Well, I'd assume $10/24 hours. On cex.io, one deposits bitcoins and uses them to purchase GHSs, which represent a GH/s of bitcoin mining power each. Once you purchase it, it mines for you and gives you the profits, which you can use to buy more GHSs. When you feel like you've had enough mining for any reason(the price per GHs rose and you want to take advantage, or you want to spend some coins, or you are fearful of imminent bitcoin-fiat price drops, etc) then you resell your GHs on the market at the current market price less any fees. You can then transfer your balance to a standard wallet for spending or sending on to an exchange to sell for fiat.

If such transactions are used, why even include them in a secondary sharechain? Why not allow nonces to be submitted to the blockchain as txns directly? A minimum difficulty could be set to target 250 such nonces per block.

In addition, regarding your concern with the multiple tiers and a high-power one spoofing a bunch of low-power ones, the address to pay to might be included as part of the transaction, so, for example, the person with the high-power rig would mine 1ImmaMineALotiubygbubfg97b3.nonce1, 1ImmaMineALotiubygbubfg97b3.nonce2, etc... while the smaller miner would mine to their own address. Thus, nonce-spaces wouldn't collide. Or am I misunderstanding something?

How reliable has PBMining been for you? The PBMining bitcointalk user doesn't have any trust entries. Personally, I've used cex.io (but have been a bit wary recently of their power edging closer to 50%). Small bumps in the road awaiting them to credit the deposit I send, but everything worked smoothly after that bit of trouble.

I am also looking into GAWMiners (see signature) to buy scrypt miners as I haven't seen too many well-vouched scrypt rent-a-miner services that owned miners instead of acting as directories of miners.

My trust rating has been amended, I'll try to be careful to keep it positive for the month.

First, SHA512 isn't a form of encryption. A hash by itself isn't really a virus. However, certain parts of the blockchain do contain patterns that might appear to be parts of viruses, although as most antivirus programs do not understand the structure of the blockchain, they're likely not aware of what the "meaning" of such signatures is in certain contexts and flag it down nonetheless.

I've been posting in that auction a few times, it seems that the seller can't even provide details on how the website was written (e.g. types of database, etc). He tells me that the programmer is "on vacation", and after realizing the auction ends before that programmer "gets back", extends it to be barely sufficient to get these details.

The programmer could very well be on vacation but I'm highly skeptical.

What kind of activity "threatens" his dealings? Not going through his escrow? Going through a competitor?

I personally didn't go through escrow, and after having contacted him regarding the loan I had running, my entry was amended to reflect the completion of that loan.

Thanks for working with me on this, I'll try my best to get it resolved. No reason to really leave since I'll be posting on the forum anyway and there aren't many other sig campaigns that aren't scams.

The trust, as you can probably see from the link, is "abuse of trust system" for a misunderstanding of rules of lending (I was neither the debtor nor the creditor). I've deleted my offending trust entry, so I'll see how this all ends up.

Technically, if the offending data in the blockchain is properly sanitized before being processed (including correct buffer allocation), and never executed directly, it should be fine, right?

Well, I'll be posting on the forum anyway (sig campaign valid or not), so I'll see how it goes. I've send a PM to the person sending me negative trust and am awaiting a response so far.

I got dumped with a vague negative feedback and am working to resolve this, am I at risk of being excluded from this sig campaign?

That seems interesting, I'll play with the idea a bit more on paper to see if something trustworthy can be found.

Thanks, that appears to clear up my understanding of this.

PHP? What version? What coin processing backends? What database? How clean and documented is the codebase?

Imagine that you asked me what car I drive and I told you that I drove a gas car. Useful? Maybe. Could be more specific, however.