With such a network difficulty, solo is unrealistic

Why not? If the pool with 150kH/s can have 20 blocks per day. So my private pool with 15kH/s should have 2 blocks maybe more if I will have good luck.
I totally ignored the initial question in my previous reply. You should be good with the pool you have installed, I used the same one. Found one block, but used the wrong Sumo wallet for payments and fixed that. What is your "pool_info.log" saying? It should be something like:
2017-11-29 04:20:55 (Thread 1) Block e5ded9 found at height 75025 by miner Sumooxxxx - submit result: {"status":"OK"}
2017-11-29 04:20:56 (Thread 1) Blockchain height changed to 75025, updating template.
2017-11-29 04:20:56 (Thread 1) New block to mine at height 75026 w/ difficulty of 514456742
I don't have accepted block yet

What is the unlocker? The whole log says "No blocks candidates in redis" like every 30sec.
I am not an expert, but I think whenever a block is found, it's put into redis. The unlocker process is for releasing the block out of redis whenever the payments are done. This is what my log said, when I found the block (I filtered all the duplicated records):
2017-11-29 04:19:52 No blocks candidates in redis
2017-11-29 09:43:28 No pending blocks are unlocked yet (1 pending)
2017-11-29 09:43:58 Block 75025 donation to Sumooxxxxx as 0.001 percent of reward: 36465171
2017-11-29 09:43:58 Unlocked 75025 block with reward 36465170800 and donation fee 0.001. Miners reward: 36428705629
2017-11-29 09:43:58 Block 75025 payment to Sumooxxxxx for 1479464125 shares: 36428705629
2017-11-29 09:43:58 Unlocked 1 blocks and update balances for 2 workers
2017-11-29 09:44:28 No blocks candidates in redis
You should really look into your "pool_info.log" around the time that you found your two blocks.