1. Will I be able to temper it?
yes you can still temper it. tempering will re-roll your base stats only, the compounded stats still remain the same. but if u're gonna refine the eq, temper before refining as a higher base stat would make the increase per refine level higher. but if you refined it before you temper, the increase per refine level after tempering follows the original old un-tempered stats.
2. If so, will the compounds be lost, or will they remain intact?
compound stats remain there, unchanged.
3. Are the tempering stats completely randomized, or do I have much more chances to get bad stats, and low chances of great stats, when tempering?
As Zegridathes said, its harder to get the higher stats from the remper range. but if u're lucky enough, you could get it in just a few tempers.
4. If so, is it dependant on a stat (such as LK)?
tempering is completely random, *maybe* biased towards the lower range *slightly* more than the upper range. none of the ingame stats affect tempering, i guess its just your real life luck