Of course. Diversification is good in every industry, especially in cryptocurrency, which is aimed for people who value freedom. I'm glad that new cryptocurrencies have chance to achieve success and they are competitive to those who are on the market from quite long time (like in case of FuturoCoin, which despite being only one year old currency has become the first one which is sponsoring one of Formula 1 teams: https://newsroom.futurocoin.com/new-currency-for-aston-martin-red-bull-racing/ )

As for me, I would point FuturoCoin as worth of attention. It’s vastly developing, after only one year it’s already present on 11 exchanges. In addition, this is the first crypto which is the sponsor of Formula 1 racing team.
But still, this is only an opinion of some guy from the internet, you should check their website: https://futurocoin.com
And do your research about other altcoins, who know which will be the most suitable to you.

It’s hard question. On the one hand, something well checked , like Stellar or Ether, would be a wise choice. But on the other, choosing something new and innovative, like FuturoCoin, may be more risky but also more profitable - new coins have new perspectives on the market

Crypto world isn't perfect  - I saw this article on spam blocked b today and it makes me realize that cryptocurrency maret may have much more problems than I ever thought

I don't like to be pessimistic, but this article on spam blocked b sounds kinda bad
You think that this problem could be a danger to crypto world?

I hope so. It all depend on us. Venezuela is a good case study for whole crypto world - the most important thing in implementation of crypto is to make people trust in it, especially those one who didn't hear about cryptocurrencies before. It's already happening, but this is a slow process. Some coins become partners of big companies or other organizations (like in case of futurocoin, and their partnership with RedBull team in Formule One racing: https://newsroom.futurocoin.com/lets-start-the-season/ ). If more people see that crypto are normal (and common) then they will start to consider this a something interesting for them.

Crypto popularity will be growing, because more and more cryptocurrencies are getting involved in promotions and sponsorships (like the case of FuturoCoin, fist official sponsor of Formule One racing: https://newsroom.futurocoin.com/lets-start-the-season/ )
If cryptocurrencies will be more present in the popular culture than they will be more recognizable for the society.

I don't think it will be as good as at the end of 2017 but it will be better than end of the 2018 for sure.
Btw, here you have an summary of coins worth of invest in 2019 ob spam blocked b