Trying to take off ... Pls. help me

[Paulo da Silva]

Hello,

I thought I understood the basics to start
writing serious things with Lilypond, but
I'm getting some problems I can't rid of.

I'm using the version 1.3.36.

1. I'm getting a few warnings whose reason I don't
understand;

2. TREBLE MEASURE 2: The \stemdown \slurup seems not
to work. I'm getting the stemdown and SLURDOWN!

3. TREBLE MEASURE 3 GRACE NOTE: I need the stemup with
slurdown. I'm getting stemdown and slurdown!

4. BASS MEASURE 1-2: The slur should go from the
1st measure si to the 2nd measure si, but it ENDS
before the 2nd measure!!!

TIA for any help.
Any tips to improve this are welcome.
Paulo da Silva
\header {
        composer = "Ludovic van Bethoven";
        title = "Sonatina em -Sol";
%       subtitle = "";
%       arranger = "";
        enteredby = "Paulo da Silva \& Ana Paula";
        copyright = "1999, Paulo da Silva \& Ana Paula";
        tagline = "(C) 2000, Paulo da Silva \& Ana Paula";
}
\version "1.3.36";

papersize = "a4"
\include "paper20.ly"
\include "catalan.ly"

%{
      Entered by Paulo da Silva \& Ana Paula, 2000
%}


RH = \notes \sequential {
        \relative  do'' \sequential {
                sol2(^" "^1^\textscript "Moderato (1/4=88)" "Large"_" "_\textscript 
"dolce" "italic" \grace {\slurdown si8^3(} \slurboth la8 sol la si |
                ) sol4 sol'8^5( \> )re^2 {\stemdown \slurup [re^4( )si^2 si^3( \! 
)sol]} \stemboth \slurup |
                do2(^4_\textscript "p" "italic" \grace {\stemup \slurdown do8^3(} 
{\stemdown [si8 la si do]} \stemboth \slurboth |
                )la4 re8(^3 mi re si^1 do^4 )la^2
        }
        \bar "|.";
}

LH = \notes \sequential {
        \relative  do' \sequential {
                <sol2 si(_3_4> <fas2 do'_1_5> |
                <sol4 )si> r4 r2 |
                <re2 la'(_1_5> <re sol_2_5> |
                <re4 )fas> r4 r2 |
        }
        \bar "|.";
}

global = \notes {
        \key sol;
        \time 4/4;
        \tempo 4=88;
%       s2.* 80
%       \bar "|.";

}

LHInstr = "Piano ME"
RHInstr = "Piano MD"

\score {
        \context PianoStaff <
         \context Staff = treble <
                \global
                \property Staff.instrument = \RHInstr
                \property Staff.instr = " "
                \property Staff.timeSignatureStyle = "C"
                \RH
        >
        \context Staff = bass <
                \global
                \clef "F";
                \property Staff.instrument = \LHInstr
                \property Staff.instr = " "
                \property Staff.timeSignatureStyle = "C"
                \LH
        >
        >
        \paper { linewidth = 17.0\cm;
                 \translator  {
                        \OrchestralScoreContext
                        minVerticalAlign = 2.5*\staffheight;
               }
                 \translator {
                        \StaffContext
                        \consists Staff_margin_engraver;
               }
        }
%       \midi { \tempo 4 = 88; }
}