I found
Coral Agression chart at FINS: The Fish Information Service some time ago. Quote from the site (this is NOT from personal experience, but some people might find it usefull):
"5.2 Coral Agression chart
Also provided by Steve Rader.
I've typed in a useful table from SeaScope (winter, '92) in which Michael Paletta discusses coral aggression in reef aquaria. It describes the two major aggressive mechanisms of corals: the release of terpenoid compounds and the use of sweeper tentacles or mesenteric filaments. I found it useful because it includes a majority of imported live corals.
The entries marked with a tilde are my additions--Telia anemonies are placed above open brain coral because I've observed them burn my red open brain coral. Both types of colonial zooanthid anemonies listed seem to release terpenoids that keep mushroom polyps at bay somewhat. Also, I've included other common names I know of in quotes.
Relative Aggressiveness of Commonly Kept Reef Invertebrates
MOST AGGRESSIVE...
1) Elegance Coral (Catalaphyllia jardinei, "Tooth coral")
2) Hammer Coral (Euphyllia ancora, E. fimbriata, "Torch coral")
3) Other Euphyllia (E. glabrescens, E. cristata., "Frog's spawn coral")
4) Bubble Coral (Plerogyra sinuosa)
5) Grape Coral (Physosyra lichensteini, "Small bubble coral")
6) Mushroom Coral (Fungia actinoformis)
7) Flower Pot Coral (Goniopora sp.)
~) Telia Anemonies (Telia sp, "Strawberry anemonies; Colony anemonies")
8) Open Brain Coral (Trachyphyllia geofroyi)
9) Cup Coral (Tubinaria peltata)
10) Moon Coral (Galaxea fascicalaris, )
11) Closed Brain Coral (Favia sp, "Dead brain coral")
12) Star Polyps (Pachclavalaria sp.)
13) Leather Coral (Sarcophyton sp.)
14) Tree Coral (Sinularia sp., "Fire coral")
15) Gorgoniana (Gorgonacea sp. et. al.)
16) Waving Hand (Anthelia sp.)
17) Xenia (Xenia sp.)
18) Giant Mushrooms (Rhodactis sp., "Elephant ear coral")
~) Sea Mat Anemonies (Zooanthus sp., "Sea mat rock")
~) Ricordia Anemonies (Ricordia sp. "Sea mat rock")
19) Mushroom Anemonies (Actinodiscus sp., "Mushroom polyps")
...LEAST AGGRESSIVE" End of quote.
As to clams, Antony Calfo and Bob Fenner say in their book, that clams are quite tolerant to most everything, unless are shaded by neighboring corals.
Personal experience - coming

My frags are about to start to overgrow each other.