It has already been reported before that the SMS system is a little bit buggy sometimes. I suggest using the Google Authenticator option as Its easier and you are sure that the code will get generated unlike SMS. OP also didn't connect since March, I doubt you will get an answer, this thread seems abandoned.

Its not the company who is going to upload things, Its the users who are. The payment feature is optional and you could charge something or nothing. I also suspect that people will be earning money for simply bringing traffic to the website but I'm not sure.

I believe that they are no longer giving the API keys. I posted the thread like one month ago and the link was working fine then. The original url is: https://blockchain.info/api , clicking on "Request API key" will redirect us to URL given above which is a white page.

I'm sorry to say this, but this may not be a mistake, they probably turned into a scam. There was a couple[1][2] scam accusations against them in the last couple of months and there were no updates since then, the creator[3] of the service didn't connect since December as well.

[1] https://bitcointalk.org/index.php?topic=1125671.0
[2] https://bitcointalk.org/index.php?topic=1805191.0
[3] https://bitcointalk.org/index.php?action=profile;u=147382

I believe that the unconfirmed transaction number reached all time high as I never seen it like this before. (100,000+)
Is it theoretically possible to create a solution for the current spam attacks that we are facing? (assuming that we already have SegWit, bigger blocks, etc.). I believe that people could always do this spam attacks, even though It costs money, someone who have something against bitcoin will definitely pay for the "cause".

Leading French presidential candidate Emmanuel Macron's campaign said it has suffered a "massive and coordinated" hacking attack after thousands of internal campaign emails and documents were leaked online. The announcement came late Friday, the last official day of campaigning in the fierce election race and less than 48 hours before polling day.

Ibtimes article: http://www.ibtimes.co.uk/macrons-campaign-says-it-suffered-massive-email-hack-eve-french-presidential-election-1620267

A spam attack most likely: https://blockchain.info/unconfirmed-transactions so you may want to increase your fees If they allow doing so otherwise either submit it to ViaBTC accelerator or wait.

By the keys you mean the seed, right? It doesn't matter where you use it (phone or tablet), It will work on both as long as the Mycelium app can run on the device.

You shouldn't see it as a threat from the price perspective because It means nothing, you should however see how much Its mentioned on the news, how many shops (local and online) use it, how many ATMs does it have, how active the development is etc. Bitcoin wins in all these things beside Ethereum is not meant to be an electronic cash but bitcoin is.

Honestly, gathering a lot of funds most of the time means nothing, take Qtum, The DAO etc. some of them are scams, others are bugged etc. I believe that sometimes, In order for the project to succeed It shouldn't get over funded.

Its more then likely some people who are trying to prove that bitcoin need bigger blocks (Bitcoin Unlimited/Roger verr)?

The thing with open source, decentralized software (bitcoin) is that they usually don't have a specific team for the marketing for example, It all about the coding and everyone is free to contribute and help. So question is, who is willing to pay for the cause? advertising on T.V is definitely not that cheap.

I'm personally willing to donate for the cause, but who is going to collect those funds? That should be a known and trustworthy face on the bitcoin community like Andreas Antonopoulos for example.

The maximum amount that will ever be mined is 21 million bitcoin yes, but It's impossible for that amount to be in circulation even when everything is mined because people are losing their bitcoins all the time and they are lost forever.

Bitcoin is unlikely to become a leading currency simply because the banking system won't let it happen. Its unstoppable but won't be the main currency for sure. As for paying using smalls amounts, that's not really where bitcoin strength shows but hopefully with Lightning Network, that would be possible.

As long as you can tell If the software has no backdoors, It's truly using the P2P protocol and Its decentralized, untraceable, secure then I will keep using it (I believe that the case with Open-source only If I understood the given definitions).

It's hard to say right now, let's just wait a couple of days and see the real final results. A lot of unpredictable things could happen though, like what happened in the U.S, everyone thought that trump will not get it but he did and Hillary lost. If she ever wins, I believe there will be total chaos in France, literally. I mean, there is a lot of muslims, arabs, africans and she doesn't want any of them. It can't end good.

Here is the thing, you clearly can't convince everyone. Someone who don't care about his privacy, high fees, centralization and someone who is happy using the current banking system won't find bitcoin attractive at all. In other words, unless bitcoin is offering something they are interested in, they probably won't get convinced at all. I personally find that bitcoin is currently a little bit hard to learn and that's why most of people don't take the time to look into it.

We actually had a list of campaign managers, I suggest talking to one of them: https://bitcointalk.org/index.php?topic=1303430.0
Some one of them are not listed and others are no longer offering their services (like SFR10 - He still make awesome signature designs though). So you have Ranochigo, Luptin and yahoo62278 who is running most of the campaigns on the forums right now.

You didn't mention the payment method you are planning to use and where are you from but here is a full list of exchanges and their trading volumne (24h): https://coinmarketcap.com/exchanges/volume/24-hour/
It's not sorted by trust but It gives you an idea about how much money they handle every day, all of them should be trustworthy afaik but never keep your bitcoins there for long term, once you buy, withdraw to your own wallet.

You can't do much since they don't want to answer you, try to post that picture in their threads[1][2], If they don't do anything, opening a scam accusation is the last thing you can do (even though that won't help you get your money back but mostly warning people about the service)
If they ever refund you, remember that the fees are just ridiculous right now, there is no reason to continue using this service.

[1] https://bitcointalk.org/index.php?topic=1392468.440
[2] https://bitcointalk.org/index.php?topic=917350.3120

Credit cards deposits should be instant as far as I know but for bank deposits, It could take anywhere between 3-5 days (same applies for the withdrawal process)