1. Sandstone with clasts (lumps) of mudstone or coal or coal-ish plant remains.
2. The thin darkest mark(s) could be plant fossil; difficult to make out;
the brown mark(s) are probably not fossil.
3-5. Ferric iron oxide staining in sandstone. Iron salts dissolved in water saturating the rock gets deposited and redissolved in pulses, as conditions change, leaving different concentrations of iron oxide crystallizing in the pore spaces in the sandstone (great simplification, but I hope you get the idea). This sort of thing can happen soon after sediment starts to turn to rock, or very much later (modern day). Have a read of this on 'Liesegang rings' - http://en.wikipedia.org/wiki/Liesegang_rings_(geology)