Не то чтобы Ваш план плохой, но его стоит ещё раз спокойно обсудить.

Не то чтобы is an idiomatic softening phrase. It means something like:

• it’s not exactly that...
• not that...
• I wouldn’t quite say that...

So Не то чтобы Ваш план плохой, но... does not mean a direct contradiction like Your plan is not bad. It means the speaker is being diplomatic:

• It’s not that your plan is bad, but...
• I wouldn’t say your plan is bad, but...

It often introduces mild criticism in a polite, less blunt way.

Capitalized Ваш is a polite, formal way to write your when addressing one person respectfully.

Compare:

• ваш = your
• Ваш = Your, written with extra politeness in formal communication

This is especially common in letters, emails, business communication, and polite written speech. In modern Russian, lowercase ваш is also often acceptable, but capitalizing it adds formality and respect.

In Russian, the verb to be is usually omitted in the present tense.

So:

• Ваш план плохой = Your plan is bad

There is no present-tense equivalent of is in normal Russian sentences of this type.

Compare:

• Он умный = He is smart
• Это важно = This is important
• Ваш план плохой = Your plan is bad

But in past and future tenses, forms of быть do appear:

• Ваш план был плохим = Your plan was bad
• Ваш план будет плохим = Your plan will be bad

Both are possible in Russian, but they are not used in exactly the same way.

• плохой = full adjective form
• плох = short adjective form

In this sentence, Ваш план плохой sounds natural and neutral.

If you said Ваш план плох, that would also be grammatical, but a bit more concise and slightly more formal/bookish in tone. Short-form adjectives are common in predicative use, but not every adjective sounds equally natural in short form in every context.

So:

• Ваш план плохой = neutral, common
• Ваш план плох = also correct, a bit terser

Его refers back to план:

• Ваш plan = your plan
• его стоит... обсудить = it is worth discussing it / the plan should be discussed

Russian often uses a pronoun like this instead of repeating the noun:

• Ваш план... но его стоит обсудить
• literally: Your plan... but it is worth discussing it

Here его is the direct object of обсудить.

Here стоит does not mean stands.

It comes from стоить, which usually means to cost, but in the pattern:

• стоит + infinitive

it means:

• it is worth doing
• one should do
• it would be a good idea to do

So:

• его стоит ещё раз спокойно обсудить means
• it’s worth discussing it calmly once more
• it should be discussed again calmly

This construction is softer than a direct command and often sounds tactful.

Ещё раз literally means one more time.

In many contexts, Russian uses ещё раз where English would simply say again:

• прочитай ещё раз = read it again
• обсудить ещё раз = discuss again / discuss one more time

It emphasizes repetition quite naturally. It can feel slightly more concrete than just again, because it literally suggests once more.

Спокойно literally means calmly, but in this sentence it can also suggest:

• calmly
• without emotion
• carefully
• in an unhurried way

So спокойно обсудить means not just discuss calmly in an emotional sense, but also talk it through in a measured, sensible way.

That is a very natural collocation in Russian.

This is a very common contrast pattern in Russian:

• Не то чтобы X, но Y = It’s not exactly that X, but Y

It lets the speaker soften the first statement and move toward the real point.

In this sentence:

• Не то чтобы Ваш план плохой = It’s not that your plan is bad
• но его стоит ещё раз спокойно обсудить = but it’s worth discussing it calmly one more time

This structure is especially useful when you want to sound diplomatic, tactful, or less confrontational.

Russian word order is flexible, and pronouns are often placed earlier than in English.

So:

• но его стоит ещё раз спокойно обсудить

is perfectly natural.

You could also say:

• но стоит ещё раз спокойно обсудить его

and that is grammatical too, but it may sound a little less smooth in this context.

Putting его earlier helps connect it clearly to Ваш план and gives the sentence a natural flow.

• Ваш план is in the nominative case, because it is the subject of the clause.
• его is in the accusative case, because it is the direct object of обсудить.

Breakdown:

• Ваш план плохой
  Ваш план = subject, nominative

• его стоит... обсудить
  его = object of обсудить, accusative

A small detail: for его, the form looks the same in several cases, so you identify it here by its function in the sentence.

Yes, that is possible.

• Не то чтобы Ваш план плохой
• Не то чтобы Ваш план был плохим

Both can work, but they are slightly different in feel.

The version without был is more compact and conversational in this kind of sentence.

The version with был плохим sounds a bit more explicit and clause-like, almost as if fully spelling out not that your plan was/would be bad. In many everyday contexts, the shorter version is more idiomatic.

So the original sentence sounds very natural and efficient.

Yes. It is politely critical rather than blunt.

Several things make it sound tactful:

• Не то чтобы... softens the criticism.
• Ваш is formal and respectful.
• стоит обсудить sounds gentler than a direct command like пересмотрите план.
• спокойно suggests a constructive, reasonable discussion.

So the speaker is not attacking the plan. They are saying, in effect:

• Your plan isn’t exactly bad, but it would be good to go over it again calmly.

That is a very natural polite Russian way to express reservations.