Running full node on OSX, how to tell if its working correctly? I'm running Bitcoin-QT 0.15.01 on an iMac (4 GHz Intel Core i7, 40GB RAM). It seems I am receiving the latest blocks, but is the rest working as it should?

I have opened port 8333 on my router and bitnodes is reporting that my node is accepting incoming connections.

Core reports 19 connections to the network but the log has a lot of errors like these:

09:20:08' progress=1.000000 cache=64.8MiB(478821txo)
2017-10-01 09:21:26 connect() to 65.130.52.89:8333 failed after select(): Connection refused (61)
2017-10-01 09:21:36 receive version message: /Satoshi:0.14.1/: version 70015, blocks=487780, us=N.N.N.N:8333, peer=1634
2017-10-01 09:21:44 receive version message: /Snoopy:0.2.1/: version 70001, blocks=0, us=N.N.N.N:8333, peer=1635
2017-10-01 09:21:44 socket recv error Connection reset by peer (54)
2017-10-01 09:21:46 receive version message: /Satoshi:0.14.1/: version 70015, blocks=487780, us=N.N.N.N:8333, peer=1636
2017-10-01 09:22:28 receive version message: /bitnode.lee/: version 70015, blocks=487780, us=N.N.N.N:8333, peer=1637
2017-10-01 09:22:49 UpdateTip: new best=000000000000000000792640fb97fb9a8ed07ba99b37479a48ebbeff3b1c1044 height=487782 version=0x20000000 log2_work=87.201974 tx=258394764 date='2017-10-01 09:22:42' progress=1.000000 cache=64.8MiB(479294txo)
2017-10-01 09:23:27 ProcessMessages(version, 111 bytes) FAILED peer=1638
2017-10-01 09:23:37 receive version message: /bitnodes.21.co:0.1/: version 70015, blocks=487780, us=N.N.N.N:8333, peer=1639
2017-10-01 09:23:39 Pre-allocating up to position 0x7000000 in blk01013.dat
2017-10-01 09:23:39 UpdateTip: new best=000000000000000000a86b2c788d7d3acd3493b05b2e8a626d7a5aca20a3ecc1 height=487783 version=0x20000000 log2_work=87.202013 tx=258397039 date='2017-10-01 09:23:00' progress=1.000000 cache=65.1MiB(482014txo)
2017-10-01 09:23:51 UpdateTip: new best=0000000000000000004927be61b84dc22202b49e55e635ce746023436c1ed14d height=487784 version=0x20000000 log2_work=87.202051 tx=258397146 date='2017-10-01 09:23:51' progress=1.000000 cache=65.2MiB(482144txo)
2017-10-01 09:24:04 socket recv error Connection reset by peer (54)
2017-10-01 09:24:07 receive version message: /bitcoin-seeder:0.01/: version 60000, blocks=350000, us=N.N.N.N:8333, peer=1640
2017-10-01 09:24:18 receive version message: /bitcoinj:0.14.4/: version 70014, blocks=437811, us=127.0.0.1:8333, peer=1641
Those are not errors/are benign errors. You have multiple connections and your node can be found on bitnodes. Your node is fine and working correctly.