Staircase questions

Not sure if these belong in flooring, but I couldn't find a more logical place either.

First - we have an inside staircase that consists of 2 steel stringers with wooden treads. I am intending to add risers to it. At present the treads do not overlap, but most enclosed steps I have seen do overlap by about 10 - 15mm or so. Should I aim for vertical risers and have minimal protrusion of the tread beyond the riser (there would be a small 3 or 4 mm protrusion as the botton edge of each tread is chamfered), or should I angle the risers back slightly to allow more of the tread to protrude?

Second - I am thinking of removing the old steel balustrade and adding a timber one. Currently the steel one is bolted down into the treads. There is no wooden stringer on the side of the steps and the steel ones are underneath and offset more towards the middle (by maybe 150mm or so). What is the best way to fix the vertical wooden posts to this sort of staircase?

Thanks

1st) vertical. keep it simple

2nd) bolt a steel T shaped footplate into each of the existing balustrade holes on the treads then bolt your new timber balustrade to the upward pointing legs of each T