From earnest loonies like this. The possibilities of disaster are rather high.

However, if you assume perfect technology, here is a better solution:-

Use the slingshot Method on Earth to speed up its orbit and so shift it outwards.

For the other body, use Mars, and shift it slightly inwards.

Engineer a distant capture so that Earth and Mars become a binary planetary system (I guess the Moon would continue to orbit Earth close in while Mars would orbit both at a distance of 5-10 times the Moon's orbit).

The result - double the surface area in the habitable zone, and Earth-Mars transit times of about 20 days.

Of course, there's always reality!