TWR - your OP refers to the question of whether we are racist, or is this a serious problem.
The two are actually not connected, so I cannot give an 'either / or' answer.
Speaking personally,. and I have commented on almost all the threads to which you refer -
Is mass illegal immigration a serious problem? Yes it certainly is.
Does seeing it as such, and referring to it as such make someone a racist? No, it certainly does not.
I am not against mass immigration because of the ethnicity of the migrants - which would make me a racist - I am against it because of the sheer number of practical, legal, social and logistical problems it creates.
I would feel exactly the same if every single UK born-and-bred ex-pat decided to return here - it's about numbers, not skin colour.