The study material on DQ Edge is sufficient. If you are preparing for UCEED, then you can refer to the following on DQ Edge
Overall, there are over 1000 high quality questions for you to go through. Almost all questions have answer explanations and many questions have additional external resources that you could dig deeper into. So go through this in as much detail as possible and it will be sufficient for you to be confident.
Those questions you mentioned are absolutely correct. Check them once again. Read the question carefully and check the correct option ID carefully. There is no problem with those questions but if you still want you can challenge those. That is upto you.
There is a difference between “score” & “Rank”. Each section has a score. How good each score is, depends on the scores of other candidates as well.
Eg. A score of 25/100 in CAT will be good, if the highest score in CAT is between 25 and 30. A score of 50/100 in CAT will be bad, if the highest score in CAT is between 60 and 70.
Hence the score is relative and cannot be predicted at this stage. You would need to wait for the results to come out.
To get final admission into NIFT B.Des, your final rank is dependent on how you perform in each section
CAT - 50% weightage
GAT - 30% weightage
Situation Tes - 20% weightage
What this means is that your performance is CAT is the most significant and will get you the highest possibility to get a good rank in NIFT.
With just your score of 250, it would not be possible to predict your rank at this stage. Getting into an Architecture program will depend on the rank you get. This is dependent on the difficulty level of the exam and the number of students taking the test. So for now, sit back and relax. Wait till the ranks come out. Having a look at the 2018 cut off ranks should give you an idea of which rank can get you into an NIT.