vals- the tips that have been trimmed will likely turn brown. watch for new leaves sprouting soon if the plant is healthy. also untrimmed leaves can develop a reddish color at the tips or wherever the lighting is highest. not a concern unless the leaf is falling apart completely and the plant isnt growing. increasing leaf length is a great sign.
branches- boiling AND baking are my favorite methods. boiling even helps them sink faster and leaches out the tannins.
I plan on getting some vals for my low tech nano setups.
They're supposed to thrive in low light and high light is what I hear. I hope they work ouf for you! I think they would look beautiful in there! They definitely have the height to fill that vase! And seeing fish or shrimp roam through them would be so nice!