Using haraam earnings for hajj, getting married or building a masjid

If a person had amassed immense wealth made up of trading in haraam, and then repented to Allaah [from that], is it then permissible for him to perform hajj using this wealth, or donate to charity from it, or [even] get married or build a masjid using it?

He stopped fasting and praying for a number of years

Whilst studying abroad, a man abandoned the prayer for a number of years, and he [also] stopped fasting for three years. When he returned back [home] to his country, he repented [to Allaah]; so should he make up the prayers and fasts [he has missed]?

Ridding yourself of haraam wealth

I acquired some money from haraam means, and I have since repented sincerely to Allaah. After having repented, I feared [my] wealth may be a source of loss for me, as I had also gotten married using this money. I now wish to use this money and perform ‘umrah and hajj with it, so what is the opinion of the shaykh regarding that?

The ruling regarding hajj without a permit

What is the ruling regarding [performing] hajj without a [government-issue] permit; there are some [hajj services] groups which don’t have a [government-issue] permit – and they take along with them pilgrims who [also] don’t have a [government-issue] permit. Is such a hajj considered correct? And are these people liable for sin when they fulfill an obligation in this manner?