With a home built on/in a high water table area comes the possibilities many other homeowners dont have to worry about and that is water coming up through floor cracks/drains as well as water that can enter walls through cracks & other outisde openings.
If you have lived in this home for a few years and the ONLY water you ever had was when the S pump failed, and now you have fixed that by adding a back up, then you have done the preventive measure needed to control the water level under your bsmt floor before it can rise up and enter through floor cracks etc...providing the sump is big-powerful enough, that would be the only problem. So, since putting in the back up & alarm, and it has rained hard `n long without any problems, sure seems to me yer ok, except the area(s) you state you have moisture.
Do you see this moisture on 1 wall,2..etc?
Is this moisture at near where you say you have a vertical crack? Or is it around where a gas line or other line enters the basement wall?
Many salespeople for inside water diverting companies will use scare tactics and all kinds of bs 'supposed good' reasons to extract money outta ya`s, thats how they make a living! The more they sell, the more they make...self-interest. It is my 25+ yr hand-on opinion(with many many many homeowners who now unfortunately know)that an inside method does NOT stop water from entering a basement wall,will not stop-prevent mold,radon gas,and will not help lessen lateral/hydrostatic pressure that is on-against the outside of bsmt walls, only an Outside method done correctly will accomplish this.