Problem 1: correct final but -1 out of 10 points for (10+j10)/110 (missing imag part in the denominator, though you got the right answer numerically)
1b: 0 marks (hint, Pdel=Pincident*(1-mag(gamma)^2) here power is linear (watts)
1c: -1 of 10 (SWR is always above 1, can't be below; swr less than 1.2 is "good" low standing waves; 1.2<swr<2 "moderate", SWR>2 bad.
1d: full marks
2a: -3 of 10 (s-parameters are sqrt of power, always use 20 log10( bn/an). You did on s11, s22, but not s12, s21.
final grade: 37/50=C+