Perhaps @thedudeabides will chime in too but here are my thoughts:
1) I experience the same thing where you lower the bid on SmartBid and the cpc's actually go UP... really weird lol... doesn't always happen but does often enough...
2) Following from that, with the SmartBid its really about letting it "find a groove" and then leaving it alone to do its thing
3) As a result, I would clone a couple new versions at different bid levels... maybe one where you bid .10$ ... one where you bid .30$... and one where you bid 0.55$... they may all end up with the same cpc.. but really the cpc is irrellevent by itself, all that matters is the CPA and ROI. The SmartBid is extremely powerful- it's more akin to Facebook's pixel than it is to anything else on Native. It can find you leads, it just depends on getting the right combination of ads + bid + etc.
4) The most important thing on Taboola is ads. Focus on finding the right ad and that is 90% of the battle 
PS Just to confirm - you are passing the conversions to Taboola right? I gathered you were from when you referenced the S2 but just wanted to make sure, as that is what the SmartBid will use to optimize obviously.
Where is most of your traffic coming from, traditional native or push sites? What's your approach on blocking sites?
Also, you say that you are rotating 3 landing pages and 2 offers.
I think not all of them are converting equally. What are their results so far? Even though it might be too early to say, are you noticing any winner so far?
@vee882 can you please add stats screenshots for the landing pages and offers too, not the ones from the calculator?
Hey so my first impression is that I think an $8 and $11 payout lead offer is going to be very hard to make work on US Desktop traffic. Then again I haven't run an offer like that in some time. What is required for the conversion? Are there any $15-25 auto insurance offers you could test instead?
You're going to need some really good ads to be able to do much scale and turn it profitable. Thankfully looking at your ads they actually do look great and they have solid CPMs too even at low bids. Generally anything over $0.25 vCPM allows you to spend low 4 figures a day.
FYI don't put much stock in
Regarding overall strategy, trying not to get sucked into the day to day stats in the beginning. The objective of launching at high bids and easing back is to make sure the ads get traction on higher quality sites like MSN properties. Are you or were you serving there at all btw? From there the game is really just lowering bids and raising daily cap over time as much are your ad CPMs allow to turn things profitable. It's hard for me to advise on the $50/day approach because I've never really gone that route even though I imagine it could work in theory if you're going super low on bids. You'd probably have an easier time doing that with mobile traffic though and a non-US geo.