No apologies needed, these are very good questions. middlecoin doesn't need to use other pools, it can just mine directly as a peer on those networks because of the huge hashpower, thus it gets 100% of the block payout with no fees for someone else. Some of the newer badly designed altcoins have to be mined directly on the network or the delays and latency of using another pool would cause a terrible payout percentage.
Is there a minimal reasonable hashrate for direct mining, like 1% of network hashpower? Middlecoin is pretty big now, but I assume it started out small and used alt pools for mining at least for a while? I'm wondering how it got off the ground if it first had to use middle men.. or am I assuming too much, did it attract a lot of hashpower immediately?
Yes, any hashrate below 1kh/s is not being reported in the stats.
Also you need at least 0.001 BTC collected in 7 days for a payout to be reported in the stats.
Regular users may collect >0.01 BTC payments in their first day and get paid and reported in the stats.
As for the bootstrapping, yes you can use a lower starting fee and pay the fee for other pools and grow like that.