About the quests being hard. When you are in the last part of the event. Every quest is supposed to be hard. Maybe some are easy for one player specifically but for other players that one might be very hard. And another quest might be very hard for you, while its very easy for others. For example the scout or research is a lot different for a chapter 2 account, versus and end tech account.
About getting the same quests in a row. I can tell you that we are working on this already, but i cannot make promises that this will make it into this event still. The key is to prevent repetition of the exact same quest condition, without making the quests too predicable again. So it needs some coding.
it is easy to prevent same quest in a row, you just need to add a simple formula to the quest roll
you have for example at the beginning 20 quests (q1, q2, q3 .....q20) with 2,5% chance to get them.
If i get q9 as first quest in the next roll for quest q9 i should have 0% chance, you take the 2,5% divide it to 19 (result 0,13157) and add that to the chance of the other quests,
so after i complete q9, i have
0% chance to get q9 because i just finished the quest
and 2,5 + 0,13157 = 2,63157 % chance to get the other 19 quests
then if i get q14 as next, again you drop the chance to 0% for quest 14 and divide the 2,63157% to 19 and add them to the other quest
so i will have 0% chance to get q14,because i just finished the quest
0,13850% to get q9 (because q9 was 0) and
2,63157+0.13850 = 2,77007% chance to get the other 18
and so on,
this way after each quest you increase the chance of the quests i did not had and keep low the chance of the quest i already had