During the recording, I checked the audio interface to make sure it didn’t hit the ‘red’.
I also moved the fader of input channel as well as the output one a little bit down to avoid clipping.
No ‘red’ was shown in the output channel.
However, when I went to do some inserts most of them showed ‘yellow’ (as shown the picture below).
What does that mean?
The export sounds normal most of the time but when it comes to loud notes little cracks can be heard.
One more question:
I read tons of articles talking about vocal recording and mixing on the internet. They suggested to apply EQ and filter to remove the useless bandwidths. As I am on the Element version, does it mean I should use the insert “DJ-eq” for doing this?
The input of your compressor reached a maximum of +15.7 dbfs. It might be that the plugin before the compressor causes this.
FYI: If you record in 24 bit you do not need to record “hot”. 1 bit within a 24 bit system has already a higher resolution than the complete 16 Bit within a 16 Bit system. To put it simple: Don’t just stay away from red, stay away from yellow, too. 
Edit: A little more explanation about the common myth to record as hot as possible, especially in 24Bit era.
Leaving noise issues aside a 16 Bit system can record 65536 different volume levels. That’s 4096 different values per bit.
A 24 Bit system can record 16777216 volume values. That’s 699050 values per bit. So even if you record at very low volumes you can record a very fine dynamic resolution. Of course you want to keep the signal to noise ration high but there is no need to drive the volume to the converters near maximum. I would say -18db is okeish.
I read tons of articles talking about vocal recording and mixing on the internet. They suggested to apply EQ and filter to remove the useless bandwidths. As I am on the Element version, does it mean I should use the insert “DJ-eq” for doing this?
Just use the channel EQ. The DJ-EQ is not really meant for this kind of task.