Buddhist marry a non-Buddhist

Celibacy and being a monk is the best ofcourse but for those who are considering life-long relationships with people who are coming from different religious backrounds must becareful. Buddhist way of living and thinking leads you to non-self, liberation from the ego, doing good things to all living beings, purification of the mind, freedom from suffering and Nibbana while some of the belief systems leads people to the completely opposite direction. And these belief systems/cultures really influences people's minds deeply. Ignoring the truth is not benefical.

Not associating with fools, Associating with the wise, Honoring those worthy of honor; This is the greatest blessing.

https://buddhasadvice.wordpress.com/friendships/

Ofcourse everyone is free with their choices, Buddhist way is not banning people's free choices and desires. But especially those who are involved in spirituality/meditation must find right people to create friendships/any kind of close relationships.

Would it be recommended if the other partner's faith dictated that the Buddhist partner would not go to heaven and so creating a deep seated question of faith and tension between the 2 people

Depends on personality.

Not recommended if both are religiously extreme. This bi-polar of beliefs will eventually end up as arguments and a convert from either side is eventual.

Recommended if the Buddhist Husband/wife is very accepting and able to keep all the belief conflicts in his/her own thoughts. Or, another way is that the Buddhist can convince the Christian that Heaven/God/Godly beings are impermanent.

Also what would anyone learn from a couple who have disbanded their own faiths for mortal desires rather then an actual spiritual journey?

Well. For the Buddhist to disband his/her belief, that means they might have disbanded the Dharma...Hence the worldly journey goes on, while the spiritual journey stops.

He/she may eventually reject the ultimate reality, and accept the worldly reality as truth. Ignorance continues to precede wisdom. The implications are of course...pretty obvious.

some have advised that religion does not matter

You might like this answer. I think it's based on suttas.

It doesn't say religion is important:

Leave aside unproven traditional criteria: including race, caste, gender, and external appearance (and creed)

Instead it says,

Find wise people who cause no fear or worry. Look for someone who is compatible in four ways:

• Similar confidence in spiritual development
• Similar respect for self-discipline
• Similar respect for humanistic practices
• Similar level of wisdom

These similarities are "so important for a peaceful marriage".

But the "confidence in spiritual development" might be exactly what you're talking about (e.g. confidence in the Dhamma) -- so maybe that is important -- better if your partner doesn't have no confidence in your (spiritual) development, and vice versa.

I married a devout Christian in 1982, then took refuge in the Buddha, Dharma, and Sanga in 2002. It is not ideal, since she believes I will spend eternity tormented in hell, but this is samsara, it was not meant to be ideal. She is a sincere practicing Christian with tremendous compassion for sentient beings. We are apparently bound together by karma and I consider her to be one of my spiritual guides. OTOH, if given the choice, I would recommend you marry someone with the same view. Samsara is difficult enough without arbitrarily making it moreso. And religious practice is easier and more productive with less obstacles.

There is no problem for a Buddhist and a non-Buddhist to enjoy a married life together.

However, the Buddha recommended couples to be in tune in conviction, for best results, in the Samajivina Sutta:

[The Blessed One said:] "If both husband & wife want to see one another not only in the present life but also in the life to come, they should be in tune [with each other] in conviction, in tune in virtue, in tune in generosity, and in tune in discernment. Then they will see one another not only in the present life but also in the life to come."

Husband & wife, both of them
having conviction,
being responsive,
being restrained,
living by the Dhamma (the Buddha's teachings),
addressing each other
with loving words:
they benefit in manifold ways.
To them comes bliss.
Their enemies are dejected
when both are in tune in virtue.
Having followed the Dhamma here in this world,
both in tune in precepts & practices,
they delight in the world of the devas,
enjoying the pleasures they desire.

There is no prohibition on Buddhists marrying religious non-Buddhists. Of course, if a Buddhist who does not believe in a Supreme Creator God, is married to someone who thinks that belief in a Supreme Creator God is mandatory for a pleasant afterlife, this produces some lack of compatibility between the couple, but this does not make marriage impossible. It is simply not optimum.