As for curiosity around utilization padding, perhaps it also stemms from being over-worried.... In these uncertain times, what if, what if...
Here you're describing a backup card, which makes sense and is a reasonable motivation for wanting a high limit. A card could go south, either momentarily (e.g. a terminal balking), for a few days (e.g. a fraud situation), or permanently. In a situation like that, you want to be able to pull out another card and hit the ground running with minimal disruption.
With backup cards, it's possible that the rewards structure might be less than ideal, but you'd have your limit to keep you from being totally up a creek. AMEX is good in this situation because they give out high limits without necessarily requiring a lot of spending. What keeps AMEX from being ideal is its acceptance rate.
I'm unimpressed by total credit limits, though. If math would allow me to have four 15k cards and a total credit limit of 40k, I'd be happy. Being able to work within the 15k on an individual card is what's important.
Definitely agree with @HeavenOhio. Not sure what the point of growing TCL other then UTI padding but if it's for bragging rights, I'm all for it.
On the other question - since the options stated are as follows - BCE, BCP, ED, EDP, Cash Magnet. I would drop the BCP simply because of the AF. An AF does not increase the chance of having a higher SL. I have the BCE and have done a fair amount of research on the BCE/BCP and in the end, I ended up with the BCE simply because I didn't see any difference between the SLs and also, the AF. I would also drop the EDP for the same reason. That leaves you BCE, ED and Cash Magnet. Out of those 3, IMHO, I'd go with the BCE. Decent rewards, 3x CLI on day 61, chances of growing are pretty good. Either that or the CM. As always, YMMV.
You'll likely be presented with an upgrade offer and a bonus at the one-year point if you start out with a BCE and decide that a BCP will be a better fit moving forward.
I want high limit cards too