I can understand why you want to make these rules (as too I am also a casual gamer and I also understand that it is not fun fighting Netlists or lists designed to curb stomp and table you every game). but these rules do appear a bit too strict
imo, I agree with only one and the group I play with are already using this rule which is no
SC, as we all feel that you can pull too much broken jazz with them, (and for those reading this thinking "but what about my deathwing/ravenwing/etc" we also decided that if your chapter master/captain has terminator armour or is riding a bike, then you can unlock the same bonuses as you would for the
SC, yeah, yeah "its Illegal" but then again the aim of the game is to have fun and we don't want to penalise the player for which army he/she takes).
here are suggestions for you that our group have used that you may want to use as well for a bit of help
-Create special scenarios: just recently I played a 250pt Kill-Team game on board a Space Hulk and we used the Space Hulk tiles for the board, it was tons of fun and we all had a great time.
-Campaigns: we tried this once, and while it did kind of stop mid way that's only because some people couldn't make it during the specific days needed to come down. but I guarantee if you add a hero growth chart, decide what planet or sector you want to fight on, then make some rules for the terrain on the board, then the game would be a blast to play on and it could require your opponent as well as yourself to use more skill and strategy as if you stay in one area, there could be carnivorous vegetation trying to eat you, or maybe that specific area has just raised a spike in radiation. The possibility's are endless
Include Personal Objectives: back in 5th ed. our
TO used to give us a deck face down and we would have to pick a card at random, and read it, then reveal it when we achieved the specific objective. This was a personal objective which if we achieved gave us more points to help us win the specific game we played, it also gave us a sense that it was any man or woman's game, right until the very end which was always nice.
Make an
IA story: When I say this I don't mean make an
IA I mean create a story in which there are a number of battles that are the pivotal moments in this story and create zany rules for each mission, maybe even homebrew units as long as your group agrees to it of course?
If your still into limiting people to what they use I would suggest how Throne of skulls deal with lists (and look at their score system), as I know they deal negative modifiers to people who exploit their codex's and produce Netlists for their tournament.
You see there are more way of playing
40k than people think, often people usually think of
40k as Math hammer which I find a little dull, so Instead of limiting players, why not give them more opportunity to play around the 41st millennium and get stuck into the narrative of the setting
Hope this helps