Ideally you should prioritise and distinguish between your calls to action to optimise for conversion.
The number of appropriate actions will vary from site to site.
However, it is not so much the number of actions as the
distinctiveness of each.
Source: 10 techniques for an effective ‘call to action’
With that in mind:
A- "Add to cart" is your most important CTA so it should be a button and occupy a prominent position within the layout so it is clearly distinguishable from secondary CTA.
B- "Enquire now" helps users who are not ready to make a purchase decision learn more about the product, it's use is circumstantial and therefore it's a Secondary CTA. This could take the shape of a link so it does not compete for attention with your primary CTA " Add to Cart" while still offering help for those users who need it.
C- "Live Chat" has a different function and it's there to facilitate the purchase decision through direct communication. As it satisfies a different function and will cater for queries that touch upon all products it should be persistent and accessible from a unique point in all your product pages.
D- "Freephone number" compared to live chat which can shorten the sales/purchase process and introduce interactivity, the use of the phone channel demands commitment and time from the user and introduces an element of uncertainty (Will I be able to speak to someone quickly), so its better to have it available to the user but "hidden" behind an explicit CTA. This will reduce calls to customer support and encourage the use of the "live chat" channel.
Hope that helps