As for the tubing... you can get suction cups to hold the tubing.. use them to hold it to the bottom, and cover with gravel... I use flexible tubing under the gravel suction cupped down, and run it to a corner and run a hardline up from there right in the corner so it is barely noticeable...
I see your plant is in a pot too. It apprears to be maybe a cyypt plant of some sort from what i can see. It will do better off out of the pot, as they can get rootbound in a little pot. Use some sciccors and carefully cut the pot out from around the plants roots making sure to damage as little root as possible. Then carefully pull the rockwool off the roots as best you can, and plant it so that the base of the leaves us just above the level of your gravel... it will be much happier like that!
What kinda lighting do you have on there?... If it is the light that came with the tank, you will be limited to low light plants like crypts, java moss, java fern, hygrophilia, and anubias... If you want plants other than those you will have to invest in some more lighting for the tank...
Other than that... it looks like a great start you have there!
