Can't find the source of the problems (solo slashes, chords, and duplicate second endings)

[Brian Clements]

Windows 2000 running version 2.2.2.

Below is an entire guitar part for an arrangement of mine. I'm having 
trouble with just a couple of things:
(If you can't see the problems in the code, then you know where I'm 
coming from. If you compile it and view the finished product you will 
see the same problems I see)

1.) The first, second, and second (agian) ending just before measure 60. 
I've stared at the code for hours and can't find why its behaving like 
that.

2.) Also, with regard to solo "slashes". My \slashOn command works fine, 
but I can't see why my \slashOff command doesn't work.

3.) Why do the chords appear below the intended line?

4.) And if this isn't asking too much, how do you make the stems invisible?

I've only been doing this for 2 weeks now. So and other advice with 
regards to cleaning up code and such will be appreciated.

Thanks in advance,
-Brian



\version "2.2.2"
\include "english.ly"
\paper {
   #(set-paper-size "letter")
   indent = 7 \mm
   linewidth = 200 \mm
   interscorline = 13 \pt
         }

\header {
 title = "Theme From Peter Gunn"
 head = "00001"
 composer = "Henry Mancini"
 piece = "Guitar"
 arranger = "Arr. Brian Clements"
 enteredby = "Brian Clements"
 maintainerEmail = "address@hidden"
 tagline = "Engraved by LilyPond (version 2.2.2)"
         }

slashOn = \notes {
    \set squashedPosition = #0
    \override NoteHead  #'style = #'slash }
slashOff = \notes {
    \unset squashedPosition
    \revert NoteHead #'style }

\score {
 \notes {
  \key f \major
   \set Score.markFormatter = #format-mark-numbers
   \set Score.markFormatter = #(lambda (mark context) (make-bold-markup 
(make-box-markup (number->string mark))))
   \relative c' {
   \tempo 4=120

   \repeat "percent" 3 {
     f8 f g f16 af-> ~ af a f8 bf-> a }
     f8 c4-^ ef8-- ~ ef c ef16-> e8.
   \repeat "percent" 3 {
     f8 f g f16 af-> ~ af a f8 bf-> a }
     f8 c4-^ ef8-- ~ ef c ef16-> e8.
     \bar "||"

 \mark #9
   \repeat "percent" 8 {
     f8 f g f16 af-> ~ af a f8 bf-> a
     f8 f g f16 af-> ~ af a f8 bf-> a }

 \mark #25
   \repeat volta 2 {
       \repeat "percent" 3 {
         f8 f g f16 af-> ~ af a f8 bf-> a
         f8 f g f16 af-> ~ af a f8 bf-> a }}
     \alternative {
      { \repeat "percent" 2 {
       f8 f g f16 af-> ~ af a f8 bf-> a }}
      { \repeat "percent" 2 {
       f8 f g f16 af-> ~ af a f8 bf-> a }}}
      \bar "||"

 \mark #35
   \repeat "percent" 4 {
         f8 f g f16 af-> ~ af a f8 bf-> a
         f8 f g f16 af-> ~ af a f8 bf-> a }
      \bar "||"
     
 \mark #43
     \repeat volta 2 {
         \set Score.skipBars = ##t R1*7 }

 \mark #50
%Solo, fill in chords%
     <<
   \context ChordNames \chords {
      \repeat volta 2 {   
         f1:m7 f:m7 g:m g:m f:m7 f2.:m7 d4:dim }
       \alternative {
         { g1:m7 g:m7 }
         { g:m7 g2:m7 a:7}}}
   \notes <<
    \repeat volta 2 {
      \repeat "unfold" 6 {
       \slashOn bf4 bf bf bf }}
     \alternative {
       { bf4 bf bf bf }
       { bf4 bf bf bf \slashOff }}
      \bar "||"
    >>  
    >>
 \mark #60   
     c8 c-^ r8. c16-> ~ c4. a16 bf
     c8 c-^ r8. c16-> ~ c4. ef16 d
     c8 c-^ r8. c16-> ~ c4. af16 bf
     c8 c-^ r8. c16-> ~ c8 bf af g
     \repeat "percent" 4 {
         f8 f g f16 af-> ~ af a f8 bf-> a }
       f8 f g f16 af-> ~ af a f8 bf-> a

 \mark #69
     \repeat "percent" 4 {
       f8 f g f16 af-> ~ af a f8 bf-> a
       f8 f g f16 af-> ~ af a f8 bf-> a }
    
                  }
           }
}