Thanks for confirming. I will respond in turn to your subheadings:
Marriage Certificate: If the marriage was legal in Columbia and you have the original marriage certificate, and either of you reside in England or Wales, you can pursue a divorce here.
Custody: This is not a straightforward answer and a detailed assessment will need to be carried out - but as you are married you will have parental responsibility and she cannot make major decisions without your involvement. You would be entitled to contest any relocation. Furthermore, your son has a right to a relationship with both of you which can only be reasonably restricted if there are welfare concerns. Shared arrangements are common place these days.
Inheritance and Will: You should immediately think about putting a will in place regarding your assets and estate. However, if you make no provision for your wife and you pass away, she would have grounds to claim reasonable support from your estate and this would be her legal entitlement even if you have excluded her from your will.
Maintenance: If you give up your current employment and work at a lower salary this will limit your income and thereby preventing or reducing your child and spousal maintenance liability. However, the court has the power to assess your true earning capacity and if it is found that you have done this to prevent a claim by her then the court can make a decision and penalise you for this.
Divorce Entitlements: Given your medium length marriage and one child from the marriage, the court's starting point is a 50-50 split of all matrimonial assets. Despite the home being in your sole name, it is the matrimonial home and considered a matrimonial asset. She has home rights to occupy the property and can make a claim towards it. The court not only considers financial contributions, but also non-financial contributions such as a major relocation from a country to be here and upkeep and child-rearing. All and any property during negotiations will need to be disclosed by both of you and this will be considered, so if you buy a property now this will be taken into account.
Family inheritance: If your mother passes before divorce, this does not automatically bring it in to the matrimonial assets, but if you, your wife and your son's needs cannot be met from the matrimonial assets, then the court will take it into account.
I hope this assists you. If you found this information helpful please provide a positive rating using the stars at the top of this page. I will not be credited for your question without a positive rating. Thank you.