Maybe the problem of OpenBazaar could be the fact that they offer legal but also ilegal products. So, they don't have cleary defined customers and some people are avoiding it for the reason that they might have problems with the law.
They PR to atract the users could also be better.

Exchangers are very atractive to hackers who attack them more and more often and the funds are at constant risk. They weren't even ment to use them as wallets but some people do. It's not wise to keep large amount of coins there but sometimes we are all lazy and because we don't have enough patience to wait for transaction confirmation when we need funds to trade, we just keep our Bitcoins there.

You can find someone trusted escrow services on the Internet or you can also find some members here who are offering this kind of services. If you use members on this forum I suggest to find someone with good trust and recommendations. Maybe is the best option to use someone you know and trus, like a friend or so.

This is very harsh split of users and maybe too simple. I think I'm kind of the both. I'm waiting for price to go up so I can spend the coins, but not all and not for lamborghini (I prefer some other type of cars). But I also think that is not good to spend just everything you have. But I'm expecting for price to go up in the future.

Tesla is a very nice car, I would like to have one. Tesla represents new, inovative technologies so somehow it's logical to me that it could be bought for Bitcoins. If Tesla dealers and retailers are supporting cryptocurrencies that is a big step forward. Who knows what else could we also buy in the future with Bitcoin.

I think there are many people, especialy from the financial area, who would like that Bitcoin falls and vanish from the scene. But this is not going to happen, you can't stop the future. Bitcoin is very well established so far and can't just "die" over night. Bitcoin and cryptocurrencies are the future and pumps and dumps in price are normal and they will not destroy the Bitcoin network.

Investing in antiques is very good idea. You buy something beautiful and precious that doesn't lose its value. I don't know about specialized web sites but maybe you could try with some auction sites or online bazaars where people offer their stuff and offer to pay in Bitcoin.

Face to face trading could be risky but you could take some precausions. Always meet in the public place with other people and don't trade large amount. Don't reval more of you and your personal data then you need to. I don't see much sense in engaging some midleman, to me that would be a risk too.

We will not have to wait that long. Things are developing very fast these days and if Bitcoin will become mainstream like other currencies that will happen much sooner, 5-7 years at most.
Altgough I'm not sure about the price, it seems a bit too excessive. It will go up a lot with time, that I agree. Still, that much....But like you've said we'll see.

I mostly use ebay or amazon, sometimes local websites in my country that are good provided and popular. Sometimes even on the forums. But  I think we miss quality online market places that accept Bitcoin. And I don't have in mind those darkweb marketplaces that are selling illegal stuff and services.

Small local businesses are always interested to accept something that will make their business cheaper, simpler and more afortable and atractive to people. So a good will and patience is needed to explain them how can they improve their business by accepting Bitcoin.

I agree and highly recommend Xapo. I'm using it over a month now and never had any issues. And it's not just wallet, they offer other services like vault and their debit card. I have it and it makes using Bitcoin much more easy and convenient. You should try it.

Is it allowed to sell cigarettes online? I mean because of special tax system and control of origin. At least in my country that could be a problem.
I suggest clothes, cosmetics, accessories and digital goods, for that you will always have buyers.
Are there any special requirements and procedures if you want to register as a seller on OpenBazaar?

What about localbitcoins traders? I'm sure there is someone you can trade with. Or you can use your credit cards if you have them, I don't think that they are beeing issued in Angola is a problem. And you can always find someone here on forum who will offer his services in buying or selling, just be careful and use escrow.

Dark marketplaces are also bad for Bitcoin reputation. Some people think that Bitcoin is mainly used on such markets for buying illegal stuff like drugs and similar. I know some people that was very hard to convince that it isn't so. Also on dark marketplaces you can easily get affected with some malware or be scamed. And get in.trouble with the police.

Pump and dump are completely normal things when it comes to Bitcoin, it's just how it's functioning. So if you want to invest in Bitcoin this is something that you will have to accept. So far it's been.shown that on long term Bitcoin is good investment but you have to be clear with yourself what is your final goal and strategy.

I don't beleive that there is any legal way to earn Bitcoins vert fast. Everything takes time and process and you have to give some if you want to win some. And I don't consider gambling as a way of earning. Maybe constant source of Bitcoins, like some job or service, is better thing than fast but unreliable earning.

There is no right, wrong or clever answer to your question. Everything depends how much funds you have, how much you want to earn and how much are you ready to lose. For some decent sum is 0.1 BTC and for some is 1 BTC. I also don't know which country are you from and that could also be the factor to determine "decent" sum.

For investments is very important not to keep all eggs in one basket. So if something goes wrong to prevent yourself from big losses. Divide your investing portfolio in smaller parts and invest in altcoins (ETH), in shares, maybe some lending (poloniex or similar) and you can start with smaller amounts.

If I could I would change the speed of transactions. Bitcoin system is already pretty safe but people with their behaviour male it unsafe (keeping coins on exchangers or  cloud wallets etc.) but the hardest thing is to influence on people. And I would remove these cloud minig fraud scheems.