Thanks for replies guys

Will look into Qtum, Waves and Stratis (good mid-term holdings I guess), also ARK seems like an interesting position.
Well, at least 2-3/4 coins will be held for a long term without even touching it.
Although this thread is mainly about my long term holdings doesn't mean I won't hold some coins for mid term (half of a year or something).
I think following diversification rules will be fine:
- 50% of portfolio for low risk coins but possibly lower gains [long-term]
- 25-30% for average risk [mid-term]
- 20-25% for higher risk investments (including ICOs) [short-term]