Looking at it, these are cylindrical lithium batteries. Too bad it doesn't tell what the chemistry of the battery is cause it makes a different if lthium polymer, lithium cobalt oxide, or lithium manganese oxide.
1) Its been done using cylindrical cells. Boosted board had on their blog about the batteris of their board. One of the pics showed green wraped cells. As of today I do not know if they still used cylindrical cells or flat packs. No, I do not have one of their boards. On the community side, some have made their own packs and solder or spot weld the ends with nickle tabs.
2) There are other battery chemistries such as the ones I have mentioned, but may require a BMS due to fire hazard. I have used LiFePO4. They were the hobbyking zippy flightmax. Couldn't tell what was happening as i rode my board becuase the esc would cut out after sometime. In genereal the nomial or normal voltage of LiFePO4 to put it layman's terms is 3.3V but can be discharged to 2.8. For every other lithium battery such as lipos, Lithium manganese oxide, or lithium cobalt oxide nomial voltage is 4.2 fully charged and 3.7 when fully discharged. No special charger is needed to charge LiFePO4 beside a good lipo charger with a LiFe setting avavilable. As you can see here, the voltage difference of lipos and life batteries are shown and is a reason why the rc market is using mostly lipos. LiFe, however, has the best advantage of fire related issues as this battery chemistry doesn't cause a visible fire if puntured or destroyed where lipos will.
The green cells I mentioned earlier, the only manufacuter I know to make those in that size Boosted showed are A123, but I cannot make the claim they are indeed A123 cells cuase the photo does not show the other side. A123 uses LiFePO4 as the chemistry in their batteries. Max discharge amperage is 70amp.
I have been looking for cylindrical lipo cells in the 26650 format but the max discharge amperage wasn't at the level required.
3) Can the batteries working with the esc you specified? Yes, if the motor was drawing 1amp or there was no resistance on the motor. Would I tell you to get them? No, the batteries specified a BMS which is good, but the "max discharge amperage is only 7 amps and that is no good.
A few weeks ago I finally understand why every Lipo pack on the market is "C" rated like 25C or 60C. Im currently taking my second semester of college-level physics. One of the lectures is about charges and the unit of a charge is Coulombs. Abbreviation for Coulombs is "C". Coulombs is also 1 amp x 1 second. I can't do the math to derive amps a second from coulombs, but physics says it is. If I am right, when a battery says 25C, it means the batery can dish out 25amps in 1 second. From that I should be able to find the roght battery for the amperage a motor draws.
4) IF you did get that pack and only IF. The built-in BMS specifed in the battery's specification mean you only have to apply electricity, but you find the correct voltage and amperage to charge the pack. So almost any RC charger will work.
For the most part, keep searching as there are better packs. As I have said before, i have been searching for cylindrical lipo battery at sufficient discharge amperage because of the properties of using cylindrical cells vs flat-packs for weight, dimension, capacity, and fire safety.
