Have you gotten professional opinions on the assumption that Steem is legally closer to bitcoin, a now legally recognized currency, than it is to say, Reddit karma (prior to cashing out and realizing an actual gain at an exchange rate, that is)? I would be curious to see a legal argument from an expert in this area, should one exist.
Also, the IRS was criticized for it's guidelines on Bitcoin and is due to make some sort of follow-up in the very near future, which will clearly impact this discussion directly:
http://www.coindesk.com/us-congressional-group-calls-on-irs-to-clarify-bitcoin-tax-guidance/