Accent size and stem length

[Erika Pirnes]

Hi,

There are two things that I would like to achieve and haven't yet been able to 
figure out. One is to globally reduce the accent size. I'm reducing the size of 
the noteheads, and that makes the accents look ridiculously big. The other 
thing is to have a more consistent length for stems. In my minimal example, the 
stems in the first measure look too short because in both measures they extend 
to the middle line. Any ideas?

Minimal example:

\version "2.18.2"

music = \relative c''' {
  b8-> \repeat unfold 5{b->} b4->
  c8-> \repeat unfold 5 {c->} c4->
}

\score{
  \new Staff {\music}

  \layout{
    \context{
      \Staff
      \override NoteHead.font-size = #-.5
    }
  }
}

Thanks!
Erika