need some help in scaping..

[antitrust]

this is my 2' tank.. got some questions below, but let me first give you guys some info

Mid-ground:
Blyxa Japonica
Ludwigia Repens 'rubins'
Hydrocotyle Verticillata
Vallisneria americana var. biwaensis (not doing very well, probably because of Excel.. growing short and melting..)

Background:
Hydrophila Corymbosa 'siamensis'
Microsorum Pteropus
Microsorum Pteropus 'windelov'

Substrate:
Bottom layer abt 2.4kg of Sera Floredepot
Top layer Black Riversand

Fert regime:
Seachem Flourish (recommended dosage 1 x a week)
Seachem Flourish Excel (dose every other day)
No Co2 injection

Fauna:
10 x White Cloud Mountain Minnows (Tanichthys albonubes)
3 x Neon Tetra (Paracheirodon innesi)
5 x Black Neon Tetra (Hyphessobrycon herbertaxelrodi)
1 x Koi Angelfish (Pterophyllum Scalare)
1 x Honey Dwarf Gourami (Colisa Chunia)
2 x Otocinclus Affinis

ok now that we're done with the info, here comes the questions!

1. My Blyxa Japonica isn't doing very well... a little difficult to root.. should i push them all the way down into the substrate? will the leaves die out on me if i do so?

2. Thinking of filling up my foreground with Echinodorus Tenellus and the centre of the background with Egeria Densa or some Bacopa xxxxxxxxxxx(?) Will they do well in my set up?

3. The Hydrophila Corymbosa 'siamensis' doesn't seem to be doing very well, with leaves turning brown and mushy.. not all stalks are like that but a couple of them... some of the stalks seem to be rotting/melting away at the base, very fragile.

4. Should i go for root tabs for my Blyxa Japonica and other steam plants? i just need to push them into the substrate right? what's a good and economical brand for root tabs?