If the poll above had a 'Useful resource for Indologists and philologists' option, then I would have picked that.
Coming to the original question of how to deal with apologists' "Read-the-Vedas-before-you-criticize-Sanatana-Dharma" challenge, it can be dealt with in an almost predictable play-script narrative.
When asked to 'read the Vedas' we can press the apologists to recommend specific books which preferably they themselves have read. Chances are that they will recommend literature from their fairly parochial cult affiliations or books whose links with the Four Vedas are very tenuous. When they are called out on this, they will typically resort to excuses like, "Well, you are asking for the original Vedas. But you need to know Sanskrit for that, and it can be understood only under a genuine Guru. Truly learning the Vedas requires a holistic lifestyle change and a return to Vedic roots."
Now the debate moves into the terrain of historical claims and can be addressed accordingly, without needing to refer to the texts themselves. For one,
the language of the Vedas is not the Classical Sanskrit of the Puranas and later works, and it can be said that the Vedas are not entirely in 'Sanskrit' as it is known today (much like
the Qur'an may not entirely be in Arabic, but that belongs to another thread.). Further the content of the Vedas proper (Samhita portions excluding the Upanishads) is mostly hymns dedicated to
deities who have since been superseded by Puranic ones, and whose worship has ceased even by zealous apologists.So at this point, they need to be asked, " A return to Vedic roots means a return to what?" A return to animal sacrifices, soma binges and hereditary priesthoods?
If we do not wish to go down the route of these well-rehearsed debates, we can press the apologists to instead cite some excerpts from, say, the RigVeda which they find especially inspiring. Chances are that they will hail the 'openness of Sanatana Dharma by quoting RigVeda 1.89.1 : "May noble thoughts come to us from every side" or credit the Vedas with an attitude of agnosticism by citing the
Nasadiya Sukta.
We are then well within our rights to exasperatedly ask "Is this all?". Shakespeare seems to do better, be it reflecting upon the
tenuousness of life, or, more usefully, giving
counsel for a righteous life.