In regards to paying taxes, the most likely answer would be to declare any income you earn from your gambling as well as any earnings from owning the gambling site and from payments from your running the signature campaigns.
I have not yet bought or sold bitcoins.
Can I declare it together when I cash it out? It is more convenient (than keeping track of all this) though I will end up paying more tax this way.
I have no idea. Again, this would depend on the (tax) laws of the jurisdiction of where you live (and where you for a variety of reasons would owe taxes).
You should consult with a tax professional in regards to when you owe taxes on what income.
It is my understanding that, in the US, when someone receives bitcoin in exchange for their services (e.g. they earn a salary in bitcoin), they would owe taxes the same way as if they were paid in fiat, then the difference in value from when they received the bitcoin verses when they sold the bitcoin would count as a capital gain(loss). However please do not take my word for this (plus I understand you to not be in the US, so this really does not apply to you).
I am curious to know if you pay any income tax on your online-gathered gains through this forum and other possible online ventures as you seem to be a very active trader of the internet commerce. Do you report your bitcoins?
If you decide to declare it then don't say anything about Casinos, since you said they're illegal where you live but you will have to clarify where and how you acquired those Bitcoins.
You can say you worked for them then you'd have to tell the whole history, where you worked, whom you worked for etc. or you can say you bought those then again you'd have to tell whom you bought it from, where the money came from which you bought those etc. A Tax lawyer might give you best advice on how to go about declaring them without getting into trouble.
I meant there is no casinos in (most of) my jurisdiction, and as far as I know, online gambling is neither legal nor illegal esp. when it comes to bitcoin.
Why can't they just ban the sites if it is so, through ISPs or something? I have never came across a single site that is banned in my country.
And personally, I don't see anything wrong with playing, since I am risking my own money which I am fine with. I am sure I am not addicted to it, and only do it for the fun. Well, we should have the freedom with our own money as long as it doesn't hurt anyone or anything.
That said I don't endorse or suggest anyone and I always advice players who are risking too much to stop playing and quit it.
In most of Europe ONLINE gambling is ILLEGAL only on the UNLICENSED sportsbooks and casinos that don't hold a LICENSE yet. You will get ISP BANNED accessing these sites only if you are in a REGULATED country from where you are currently connecting. The message usually reads something about the supreme court of the country outlawing this and that and you could go to prison for couple of years and paying a huge fine.
Now bitcoin casinos are still a gray area with unlicensed casinos whose license from costa rica or wherever doesn't mean shit in your country if the goverment finds it illegal because these casinos must pay a tax for them to make it legal.
If someone in your circle reports you that you gamble online with bitcoins you may be in legal trouble because they can slap you with a lot of fines and possibly go to jail. I would suggest not mentioning any gambling sites whatsoever.
I hope that helps.
