As a general rule, citrus are *not* pruned like other fruit trees are. They need to have enough nodes to bloom/fruit and if pruned too much it really reduces the crop or you get none. Most pruning of citrus is just to remove dead branches.

If you want to shape it a bit, then just take off enough to make it pleasing to your eyes. I think you are describing "water sprouts" which are very fast growing, vertical branches. I leave them on trees that need to fill in, such as my trees that lost their tops from hurricanes. eventually the wild new growth will become more normal looking (will have brown bark)and will fruit.

If you trim the interior, you may get sun damaged fruit. The leaves give the fruit a little shade.

I don't trim my citrus unless I have to. I like the natural weeping look. My Meyer had a very wild looking, upright branch last year, I left it alone, now it has balanced itself out quite nicely.

Bottom line is, trim it if you want to, but it is fine to not trim, or just minimally trim citrus.

Lisa