One does not need to wash his hands before saying modei ani. There is a question if it can be said in a place where it is asur to say a דבר שבקדושה, therefore one should refrain from doing so.

Modei ani can be said even when still in bed.

Women say מודה with a קמ”ץ.

One should pause between the words בחמלה רבה, and then say רבה אמונתך without pausing.

There is a custom of some to say also other Pasukim, however only those with this custom should say them before washing their hands.