30 Gal Tank Suggestions. Where Do I Go From Here?

I got this 30 gal ive had for a while. The system already went through all its hiatus and has settled at:
 
Hardness: 150
Alkalinity: 100
ph: 7.3
temp: 85-88F
 
These approximates, so give or take. 
Currently i have a young and adult green barb, two rainbow killie fish (one being the domimant in the tank) a bumblebee platy and a clown barb. There were more fish who perished due to fighting and a fungal infection which i contained poorly (not looking for advice on that).
My question is: What common and exotic tropical fish would you (the more seasoned fish keepers) introduce to my aquarium? Also, im having a hard time keeping these plants alive for long. It's not just the fish killing them (Anubias and Amazon Sword). Any tips on plant keeping? Also what would be a suitable floating plant for the killie fish (besides Anacharis).
 
Many thanks in advance!
 
 

If you want harder fish to keep I can think of a couple. For a 30g you could go for hillstream loaches, youll need power heads or a filter with a spray bar that pumps at least 1000 l/ph. Or, you could go for German blue rams but you may need to invest in an RO system as they need very soft water. Alternatively, you could go for the more expensive colorful shrimp like orange eye blue tiger or cardinal shrimp.

I would first work on your current stocking. Tiger barbs really need more space as they can be rather feisty. I don't know much about the clown barb, but I do know that all barbs are schooling or shoaling (tiger barbs school, cherries shoal, I think clowns also school). Your platy will enjoy company from more of its species, as these are shoaling fish too.

So, before you add any new species, I would finish your current stocking:
2 killifish
0 tiger barbs
3-5 platy
6+ clown barb (IF they are suitable for this tank, not positive though)

Then I would add a few peaceful bottom dwellers, such as BN plecos (albino ones are really wicked). Then you could get some interesting fish such as the peacock gudgeons, perhaps some smaller South American cichlids, such as apistos. You could consider a group of otocinclus. Honey gourami. The most important thing is working on your current stock.

Completely agree with attibones. Once you get your current stock up to higher numbers, then you can think about adding more fish. A few fish I would recommend are a pearl gourami, a shoal of corydoras, a bristlenose pleco, and pristella (x-ray) tetra. If you like shrimp, amano shrimp and/or bamboo shrimp could be an option.
 
As for your plants, are your anubias species attached to driftwood or rocks? Or are they planted in the substrate? Anubias species do better if they are attached to driftwood or rocks (attaching them with a cleaned rubber band or twine will work). You will want to get some leaf conditioner to add to your water and you may want to consider root tabs for your plants in the substrate. That should get them healthy and growing in no time!

Just a thought, isn't the temperature a little on the high side? that's 30+ Celsius...

Idk if its just me but that temperature seems really high... All my tanks including my cichlid tank are sitting at 74 deg...

I'm amazed no one has mentioned this yet but clown barbs get to be about 5-6 inches. They are also an active fish so they need a tank that's about 4ft at least.
Not to mention the fact that they need to be in groups of 6+...
I would look into re homing him if i were you.
and yeah 30 degrees is a bit too hot, i'd turn the heater down a bit.

I'd actually rehome all your fish and go from there., but that's just me because I personally don't like most of those fish. And like said if you did fix your stocking you'd already be overstocked.

I love the red gravel!!!  I would throw a couple cool glo tetra's in there..  Even though they are a beginer fish they are darn cool!  they have great personalities too

I read through all of your comments and will take them all in consideration!
That's a good idea on attaching the plants to rocks or wood. I can see the benefits in that.
I'll be making a trip to the fish store later and pick some stuff up. 
Will update soon! Thank you again. 

So i ended up tossing in 4 painted platys to keep the lone one company. All five are getting along great and got a healthy appetite. 
I attached some of my plants to rocks i already had and added Nutrafin Plant Gro to the tank after a water change. Hopefully my plants will come back to life.
When i was at the petstore i saw an adult corydora spazzing under a log. I asked the store manager if he wanted it still and he gave it to me or free! It lasted another two days in my tank, im positive they were better moments than in that cramped store 5galon tank.
Thanks again for the help yall.
 
Excuse the glare, i couldn't make my room any darker. That little mount of gravel on the right side, i took a jar and buried it. So far i havent seen any fish use it after the corydora died in it. I hope they exploit the option at night tho.