The points you make regarding the benefits of S7 are both very true and valid. They sadly are wholly irrelevant as having a GW when mounted provides only +1S (the same as a halberd, except with the bonus disadvantage of always striking last).
Temple guard are lovely models. Really great. However the point of posting lists in the army list forum is to discuss army lists mostly in terms of gameplay mechanics. The mechanics dictate that TG are simply not worth it on a gameplay level unless they have a slann sitting in the middle of them. Their strength comes from the synergy of cold bloodedness, stubbornness and the general high toughness and relatively high armour of saurus.
Now to give you the undeniable facts and figures that make TG not worth it without a slann. This is coming from someone who wanted desperately to have them in his 1k list due to their beauty, who even started a thread that eventually swayed my mind (after about 3 pages of discussion) regarding whether TG are worthwhile without a slann.
TG cost 16 points. To exploit their "rock solidness" it is best to use their hw+sh 99% of the time. Plain saurus with a hw+sh cost 11 points. The sole advantage of TG without a slann over plain saurus is one point of armour... costing you 5points per model. TG's strength comes through the synergy of being tough and stubborn. TG with a slann will stay in the fight 98.9% of the time in any situation that they lose as long as some survive with a BSB re-roll (slann as BSB can be trivially assumed). Without a slann or a BSB (as I note you have no BSB) they will stay 80.6% of the time at best. This rapidly falls to 68.1%... 52.3%... 35.6%... and lower as you lose by more CR. Not to mention that without a slann the TG are no longer ITP (I guess at least this means that they can flee hahaha).
In short I think that it's fair to say that TG without a slann in it are the least efficient and effective unit possible in the army except possibly a swarm or a skink deathstar (unless charged by a large target haha). And let's not forget that asking for advice on here is asking for a judgement of effectiveness and efficiency.
It's my opinion that TG without a slann are an awful choice (and it's something I've thought long and hard about - my first painted unit was my 10TG) and as a result any list based around 3 small units of TG is a list that I am simply going to judge as awful beyond words, especially if it has flaws in basic weapon choice and EotG set-up!
Essay over; I forgive you for your impudence: saying that the TG should go is by definition constructive criticism; it is clear you just didn't comprehend just how bad slann-less TG are.