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]?