I would like to have the following clarifications with regards to it's permissibility in the Islamic context
1) Can we invest in government bonds/trust funds in a Muslim or non Muslim country?
2) Can we invest in Fixed deposits or obtain loans from non Muslim banks?
3) Can we invest in venture capital schemes, whereby we invest in halaal businesses and then sell of our investment at a higher price at a later date?

Yes you are allowed to invest so long as the investments are legal and genuine.