MS Application - Explaining past setbacks and Framing Personal Statement

So I’m applying to MS programs in the next cycle and I am here for a little help in explaining my past coursework performance.

School: Top 15 World University (US)

Major: Mathematics, Minor in Statistics

CGPA: 3.71/4.0

Math Courses: Single Variable Calc (A), Multivariable Calc (W, then B+), Intro Diff. Eqn. (A-), Intro Linear Algebra (B+), Linear Algebra I (B), Linear Algebra II (A), Real Analysis I (B+), Real Analysis II (A), ODEs (C+), PDEs (A-), Complex Analysis (B), Optimization (A)

Stats Course: Introl Stats (A+), Intro R (A-), Probability (A), Mathematical Statistics (B), Regression (A) Experiment Design (A-), Advanced R (A), Linear Models (A), Statistical Modeling (B+), Data Mining (A)

Recs: 2 Stats Profs (one alright rec, other hoping to be great), 1 Math Prof (RA II prof, hoping to be great)

GRE: 169 V / 170 A / 5.5 AW

My issues / questions are:

  1. W in Multi (1st year) + Pass in Discrete Math (2nd year) + Withdrew for Semester in 3rd Year were all due to a recurring health issue. Do I need to elaborate on this, anymore than just stating that its been resolved now?
  2. C+ in ODEs. Honestly, I just didn't understand the material and was not fully prepared for the final. Should I spend additional time explaining this situation?
  3. I wanted to tailor my profile around perseverance and improvement and that though statistics and math have always been weakpoints for me, I pursued study in these subjects because expertise in these areas would better allow me to analyze rigorously my interests in other areas. One of my letter writers thinks this is a somewhat unique viewpoint. Is this an alright topic, or will it draw to my less than stellar math and stats courses?
  4. Should I be decently competitive for good programs (>10) in my field?

Thanks so much for any help!